Everything is possible
, but it's just time consuming and for what reason would you ever waste your time on it
Therefore an automatic feature installed via Ren'Py would be waaay better
And no it wouldn't be able to show pregnancies or children of course, but only the effect of aging on the already created models. That would require a completely different engine to simulate
but still would be possible to some degree, but it would be super complicated to pull off and still make it look somewhat realistic