“Alexander” is a big family name on multiple sides, so we are considering Alexandra for a girl. It just feels a little too long and formal for us to regularly call her that, so I’m interested to hear ideas for nicknames beyond the standard Alex/Ali. I actually do really like Alex for a girl but we have a close male friend named Alex and it feels a little weird to name our baby the same thing!
I adore the nn Ally/Allie. Also, I’ve heard [name_u]Lex[/name_u], [name_u]Lexi[/name_u], [name_f]Andie[/name_f], [name_f]Lexa[/name_f], [name_u]Zandy[/name_u], [name_u]Sasha[/name_u] used for [name_f]Alexandra[/name_f]
alexandra is my name!
sandy, ally, lexie, sasha, alexa are the ones i sometimes get called by
Maybe [name_f]Andra[/name_f] or [name_f]Andie[/name_f]? [name_u]Or[/name_u] if you’re okay with something a bit more “out there”, [name_f]Xandie[/name_f] (pron. Zan-dee) could be quite fun too… And I also like [name_u]Sasha[/name_u], as suggested by others! 
Alexandra…
[name_f]Ana[/name_f]
[name_f]Annie[/name_f]
[name_u]Landry[/name_u]
[name_f]Andra[/name_f]
[name_u]Lex[/name_u]
[name_f]Lena[/name_f]
[name_u]Xan[/name_u]
[name_f]Leni[/name_f]
[name_u]Lannie[/name_u]
[name_f]Addie[/name_f]
Ada/Adda
[name_u]Lexi[/name_u] would be cute!
[name_f]Alexandra[/name_f] is gorgeous 
[name_u]Xan[/name_u], [name_f]Xandra[/name_f], [name_f]Sandra[/name_f], [name_u]Zandy[/name_u], [name_u]Lexi[/name_u], [name_u]Lex[/name_u], [name_u]Anne[/name_u], [name_f]Andra[/name_f] are the first that come to mind!
xan
lexi / lexie
lex
lexa
alexa
andra
andy / andie
[name_u]Sasha[/name_u] is my first thought. It’s a common russian nickname for both Alexander/Alexandra.
I also like [name_u]Ale[/name_u] (UH-leh), [name_u]Alexis[/name_u] and [name_f]Andie[/name_f].
I’ve known Alexandras IRL (it was a fairly popular name in my area when I was growing up) that have gone by [name_u]Alex[/name_u], [name_u]Lex[/name_u], [name_u]Xan[/name_u], [name_f]Lexa[/name_f], [name_f]Zandi[/name_f], and “just” [name_f]Alexandra[/name_f]. I think one of the charms of the name (which I love) is that there is no immediate or required nickname, and I like all the options I just mentioned. I also like:
[name_u]Allie[/name_u]
[name_f]Xandra[/name_f]
Xanna
[name_f]Andra[/name_f]
[name_f]Andie[/name_f]
[name_f]Alexa[/name_f]
[name_f]Annie[/name_f]
[name_f]Lissa[/name_f]
Lexan
Alexanne
Andrie
[name_u]Sandy[/name_u]
I remember that the last [name_f]Empress[/name_f] of [name_f]Russia[/name_f], [name_f]Alexandra[/name_f], was nicknamed Alicky by some family members. I always thought it was a pretty surprising nickname, but also pretty sweet.
[name_u]Lexie[/name_u] is so cute! Maybe [name_f]Deedee[/name_f] for an out there option.
[name_f]Annie[/name_f]
[name_f]Andi[/name_f]
[name_f]Andra[/name_f]
I went to school with an [name_f]Alexandria[/name_f] who went exclusively by [name_f]Annie[/name_f].