Didn't know where this was better suited but I just put it here....

I'm trying to write a backsory for my Altmer but I can't find anything on High Elf families and how they work. I'm also confused about how everday High Elves feel about the Thalmor and such. Any help with my backstory would be amazing!

You could look up the Direnni clan. http://www.imperial-library.info/content/de-rerum-dirennis may help but I'm not sure if that's exactly what you're looking for.

Other things to keep in mind is that they practice eugenics, many have numbers/digits as names.

I'm not sure if I could call the author of http://www.imperial-library.info/content/rising-threat an everyday High Elf (see the preface), but it's worth reading.
Altmer families are pretty obscure since they rarely use family names. I only know of three; the Dirennis, Aundae (vampire clan) and Camorans.

There is a Mothril.

I absolutely forgot about her!
Strange, she's a noble, but doesn't seem to have any (mentioned) relatives.