Firstly, I'd say begin as you mean to go on. If you don't intend to go vegan, even if this date turns into a relationship, then just have whatever you think looks good on the menu.
Secondly, if you know a good restaraunt you want to take her to, just give them a call and ask if they have a vegan menu or at least options. Most restaraunts do cater for weird food choices and/or allergies these days. Well over here they do anyway.
nb. I say weird because I really think vegans are weird. I mean seriously, how can anyone not like a good piece of meat every now and then?
