@Rozzak
Well it really depends on the scale I guess.
If it's something like swapping souls are replacing the soul of a child that they've already given birth to, that'd be pretty unfortunate. Luckily, seems that wasn't the case here.
Then there's also the question of when the baby regains their memories of their past life. If there's no interval whatsoever, it might as well have just been plain transmigration. Again, doesn't really seem to be the case here. In those 2 years without memories, despite being a baby unaware of most things, she had to be influenced to some effect.
I've thought about that as well, but really, in the end, the child that they gave birth to, isekai'd or not, is still very much their child.