Isn’t that Fred’s girlfriend they’re with?
Yes, Genoveva Casanova, there is a link to her Insta account.
I don't know exactly how old Genoveva is, but isn't there something ... odd ... about her being "besties" (at least, enough to vacation together?) with a 25 year old? [I think that's how old Victoria is?] Genoveva must be a real people-pleaser.

She's 47, and yes. But the royals, and the people who are in their circuit, are odd to say the least.
I don't really know how close Victoria and Genoveva are, but let's not forget that Genoveva was once married to Cayetano Martínez de Irujo, son of the late Duchess of Alba, so they probably know each other long time ago (Elena and Genoveva at least) as they belong to the same social circles.