I have a fix but I can't upload the source for it. So, if anyone knows python, these are the changes needed that must be made to "endings.rpy":
Lines 507 - 513:
label epilog:
$ increase_preg_score(lilyO)
$ increase_preg_score(momO)
$ increase_preg_score(noraO)
$ increase_preg_score(stephO)
$ increase_preg_score(alexO)
Change them to look like:
label epilog:
call increase_preg_score(sisO)
call increase_preg_score(momO)
call increase_preg_score(noraO)
call increase_preg_score(stephO)
call increase_preg_score(alexO)
In other words, change the "$" to be "call" and change "lilyO" to be "sisO"). Make sure you keep the spacing!!!
Then recompile the game to create a new "endings.rpyc" and play on.
If anyone cares, in order to see the pregnant endings, do NOT give them the anal attribute! And make sure you have lots of unprotected creampies with the ladies.