Yes, that's Valeria's mommy. At least she looks like that comparing to the pics we saw of her before.
That kinda puts a spanner in the works of my pet theory that Val is MC's half-sister, since two wives of Santiago wouldn't have fun together in a club. But I don't think that's her. Val's mom has to be at least 36, around the age of Emily, Melissa and Adriana. Gabi is in her late twenties. The woman also says, "Oh come on, Gabs. I've known you for over 10 years." This has two clues:
- Valeria's mom loves using Spanish terms of endearment. Why would she call her Hispanic friend "Gabs"?
- Over ten years means they met when Gabi was a HS senior or a college freshman.
The woman in the club looks like Gabi's friend from the old photo, making her the same age as Gabi, too young to be Valeria's mom.
As to why does she find the MC familiar? I'm still wondering about that. Guess it's time to look through the images again.