Vito Caiati raises an interesting theological question.

This week, I again read your post of 08/24/2019 On the Specificity of Traditional Catholic Claims, in which you question the certainty assumed by the Catholic doctrine of the [moral] immutability of the soul, and hence its fate, after death.  My interest in your thoughts on this matter arises from my pondering the question of the doctrine of immutability in relation to those of salvation, either immediate (Heaven) or eventual (Purgatory) or damnation (Hell) as these concern the loved ones of departed persons. Specifically, I am thinking, for example, of the deep love of a mother for her children. If it is the case that the soul of a loving mother finds, through the meritorious life that she has led, immediate salvation in Heaven after death, but that of her child, lacking in such virtue, ends up in Hell, is it rational to belief that the former soul is happy or at peace? In following up this question, I turned to the Stanford Encyclopedia of Philosophy, which has an entry on “Heaven and Hell in Christian Thought,” which, assuming the inclusive nature of love, “especially in the form of wishing the best for another” (Section 4.1), poses the question in the following way: “How could anyone remain happy knowing that a genuine loved one, however corrupted, is destined to be miserable forever”? (Section 5.2)  More generally, how is it just to allow souls to become embodied and to form loving relationships if such an end awaits so many of those who are loved?

One answer could be along the lines of what I say in Soteriology for Brutes? which ends as follows:

[Edward] Feser makes a good point, however, when he says that the Beatific Vision will so entrance those of us who get to enjoy it that we will give no thought to our sublunary animal companions. But this is consistent both with their survival and with their non-survival of their bodily deaths. Perhaps my cats will go to cat heaven where they will be compensated for their suffering here below, and I will be so swept up into the Visio Beata as to give them no thought at all, any more than I will give any thought to that Gibson ES 335 that I never should have sold.

One might speculate that the saintly loving mother who goes straight to heaven upon death will be so swept up in the ecstasy of the Beatific Vision as to give her children no thought at all.  All sublunary concerns will fall away in the presence of the infinite reality of the divine life.  She will no more think of her children than I will think of my cats after I have served my 'time' in purgatory.  Ed Feser, however, would not and could not give this answer given his strict Thomism. Thomas famously states that “The blessed in the kingdom of heaven will see the punishments of the damned, in order that their bliss be more delightful for them.” So we get the curious and indeed horrifying result that the saintly loving mother who loved her child in time will experience schadenfreude at the child's unending torment in eternity.

Part of the problem here is that we quite naturally tend to waffle between two very different conceptions of the afterlife. I call them Life 2.0 and Beatific Vision.  I explore the difference in considerable detail in  Conceiving the Afterlife: Life 2.0 or Beatific Vision?

Thomas himself may be waffling. If the souls of the blessed in heaven are wholly absorbed in the infinitely rich and endlessly variegated, and thus not possibly boring, absolute life of the Supreme Reality, how could they continue to be distracted by finite concerns? How could they continue to care about other finite persons, whether in heaven, hell, purgatory, or on earth? How could the blessed take satisfaction in the torment of the damned? But insofar as we think of survival of bodily death as personal survival, as opposed to an absorption into the Absolute that effaces personal individuality, we will tend to think of finite persons as preserved in their individuality together with their sublunary interests. 

This sort of attitude which disallows a clean break with the finite and an ascent to the Absolute is reflected in the popular song from 1941,  I Remember You. The version I remember from my boyhood is Frank Ifield's 1962 effort which features the lines (written by Johnny Mercer):

When my life is through
And the angels ask me 
To recall the thrill of them all
Then I will tell them I remember you.

The singer goes on to remember two distant bells and stars that fell like the rain from the blue. So the singer in heaven, presumably in the divine presence, is thinking about bells, shooting stars, and a woman! Now a woman for a (heterosexual) man is the highest finite object, but still a rather paltry bit of finitude as compared to to the stupendous transcendent reality that is the Godhead.  The things of finitude and flesh are next-to-nothing in comparison, and one's ultimate felicity could not possibly be thought of as attainable by way of loving and being loved by a mere mortal.  One wants to love and be loved by eternal Love Itself.  This is the sort of attitude one finds in Aquinas and such first-rate expositors as Pierre Rousselot and Etienne Gilson. I quote Gilson in World + God = God? See also Again on 'God + World = God.'

The sort of heavenly retrospective on one's earthly tenure found in the sentimental old tune from the '40s can also be found in serious religious writers such as Kierkegaard and Rabbi Joseph B. Soloveitchik. See the latter's Halakhic Man, tr. Lawrence Kaplan, Jewish Publication Society, 1983, pp. 38-39:

When the righteous sit in the world to come, where there is neither eating nor drinking, with their crowns on their heads, and enjoy the radiance of the divine presence . . . they occupy themselves with the study of the Torah, which treats of bodily life in our lowly world.

[. . .]

The creator of worlds, revealed and unrevealed, the heavenly hosts, the souls of the righteous all grapple with halakhic problems that are bound up with the empirical world — the red cow, the heifer whose neck is to be broken, leprosy, and similar issues. They do not concern themselves with transcendence, with questions that are above space and time, but with the problems of earthly life in all its details and particulars.

[. . .]

The universal homo religiosus proclaims: The lower yearns for the higher. But halakhic man, with his unique mode of understanding, declares: The higher longs and pines for the lower. 

Thus the waffling may be inevitable, even for the doctor angelicus, given the ineluctably discursive nature of finite mind.  We think in opposites and cannot do otherwise. So we think: either the individual soul is extinguished in the Godhead thereby losing its individuality — which would make hash of the notion of personal immortality — or individuality is retained together with finite concerns for other persons and things from one's sublunary tenure.  

Back to Vito's question. He asked how it could be rational to view the saintly mother in heaven as happy or at peace given the mother's loving concern for her child who she knows is in hell. The problem is exacerbated by the Aquinate asseveration, “The blessed in the kingdom of heaven will see the punishments of the damned, in order that their bliss be more delightful for them.”  My suggested answer was that the blessed, wholly absorbed by the visio beata, will have lost all memory of the finite, including the persons they loved in the sublunary. The trouble with this suggestion is that it does not comport well with the orthodox view that individual souls are never wholly absorbed into the Godhead, but retain their individuality. But if so, the deepest sublunary loves could nor be wholly effaced or forgotten in the way the old man forgets the toys he fooled with as a young boy. So I have no good answer for Vito.

One again we see that the philosopher's forte is not the answering of questions but the questioning of answers.