I should like
Robin on a girl ... but I don't. I've known many, and my impression of it is: middle aged, competent, plain. So it's not bad, but it doesn't have any appeal and it seems a little anemic and unsexy. The spelling
Robyn gives me a similar vibe to Mysti or
Krystal.
Roberta is nice but I dunno about nn
Robin. Birdy (=
Bertie, because it's ruh-BIRD-a in my accent) seems like a better nn for
Roberta to me.
I prefer
Susanna but
Suzanna is alright.
Suzanna looks 1970s-ish to me. It's better without an H on the end, either way. I like
Susan better than
Suzanna (hm. Every time I go to type the name
Suzanna, I type "Sex-" and have to backspace. Weird). I like nn
Sue or
Susie for any Sus- name.