Eh, I stopped playing this game. I am all for choices and separate routes but not when they just exist so that you repeat the entire sequences just to see some segg scenes with non chosen girls. About Rachel mother little plot it was a little stupid that she figured out he is a werewolf but not her husband who had the cuckfetish and supposedly killed alot of werewolves and even saw MC goes ball deep inside his wife pussy. Nonetheless, the choices there was just two either get fuck her or don't. Probably fucking her will ruin chances with Rachel.
She figures out that MC is a werewolf if he made some mistakes at dinner.
Like complementing on the moon instead of the fog.
Basically
HE was convinced by the corrections and flattery MC gave.
SHE was not.
If he does not make a mistake he is able to directly
TELL her that he is a werewolf.
The sex with Rachels mom is different if she does know it.
If she does not it is "normal" sex.
If she does it is rough sex with a partially shapeshifted werewolf.
Please remember Count Orlof was shapeshifted into a bat at that time.
He saw not a thing.
He "saw" with the ears of the bat that two persons were having sex but not who, why, how or what.
Since a lot of the girls got ... reworked to accommodate a harem and the girls being OK with sharing it is ... let's say unlikely it has an effect on Rachel.