The way I read this is the caring Priest would pay no attention to "Catholic Teaching" and speak to comfort that mother.
Put another way, if I’m in a theological debate and I’m asked that question, I will answer, “The Church cannot say for certain as a matter of dogma”GK Chesterton in "Orthodoxy":
But if a grieving mother asks me the same question, I would answer, “I’m sure your baby is in Heaven”
You may, at this juncture retort, “But that is contradictory; you can’t have both answers be true.”
Both answers can be true though because, one is answering a theological charge, who’s only purpose can be to trap the Church in some theological mistake, while the other is asking an honest, truly human question, that has a truly human need attached.
This is actually why the Church is quite reticent to define anything dogmatically until and unless there is sufficient reason to do so.
"Mysticism keeps men sane. As long as you have mystery you have health; when you destroy mystery you create morbidity. The ordinary man has always been sane because the ordinary man has always been a mystic. He has permitted the twilight. .....47 has not given two contradictory truths, but Chesterton's description still stands
He has always cared more for truth than for consistency. If he saw two truths that seemed to contradict each other, he would take the two truths and contradiction along with them. His spiritual sight is stereoscopic, like his physical sight: he sees two different pictures at once and yet sees all the better for that. Thus, he has always believed that there was such a thing as fate, but such a thing as free will also. ....
It is exactly this balance of apparent contradictions that has been the whole buoyancy of the healthy man."