They're both mixed because I think the idea of two of the most prestigious high and mighty fuckers in the school not being "Pure blooded" is mildly ironic.

I think Celestia feels a lot of shame surrounding her Mexican heritage, despite living in Mexico most of her life- because to her being Mexican carried this underlying implication that she was "poor," or "uneducated," due to how others treated her. she's also a bit of a fresa in my head.... girl was upper middle class trust me.