It may be beautiful and touching, Sarellah, but we do have to question the logic of the process. I don't think it makes sense for it to be the one soul(child) that has a random choice in the matter. It makes more sense, in my opinion, that it would have to be a mutual decision made by both souls before each life (mother and child) and of course the father too, I suppose, but I'm just using two souls as an example.
I don't think its plausible that a soul, in this case, the mother, could plan her own life to a degree but have no idea what soul(s) will be her child. I'm not exactly saying that when children claim the choose their parents its a false memory.. I'm just implying that the parents are most likely to have agreed to that decision before their own birth, therefore the actual choice isn't when the mother falls pregnant - it's pre-planned and agreed in the spirit world.