I have to wonder what makes anyone think Alice (or Ann/Kira who are both older and if you ignore the Patreon-safe BS both have adult children, or ESPECIALLY Lisa who probably knows less about sex than your average 14 year old because of how sheltered she is) would want Eric (or any other guy) to "knock her up."
That doesn't seem like something any version of her would want, even that bastardization of her that lets Eric abuse her in that Ren'py remake.
And what exactly would that add to the game?
A kid that's born and then never mentioned again while everyone pretends it never happened?
I do NOT want children in these games, there is no need for any of the girls to have a "bun in the oven."