I also think Ximena is mother of Val or at least very close like aunt or step-mum or something like that but Ximena is the lead of a very popular TV Series which means whatever she uses will become trendy, so it can be easily brushed off as they have both own same brand.
Yup i wouldn't call it "proof".
But it can be "mounting evidence", small coincidences that by themselves don't mean a lot but everywhere we keep seeing these small coincidences...
I hope she does turn out to be her mom, because it creates one more little group with extra tension and personal relationships... i'm already excited at the idea of making BFFs fight, mom vs daughter? HOLY SHIT!!!!
I can see something like the MC being invited to do more model work(it would require Erynn model scene) and perhaps we get to work with Ximena and things get heated

.
Or the "Entanglement" cast does a end of season party in the restaurant, Ximena gets a little drunk and a little frisky...
And things like that is why I tell the people they should play all kinds of routes and not only hunting for RP. You can see some hints about things in the game on places many players don't ever see and when it's revealed by story this people start ranting about Nyx' "teasing" and "messing with the players".
It is quite interesting the things you can glean on paths one wouldn't usually take, often giving you details you don't have in the normal route with a certain girl, and with reasonable butterfly effect.
There's not much reason to be mean to Brooke, being on good terms with her has no downsides and doesn't piss off any of the other girls, but then you get a little extra hint in there because of it.
Seeing her ass is still better though lol.