Is this a date, a thank you or just friends, going Dutch?

I met another alum of my university through our local university club; we're in a small group of alumni that meets for career benefits.

I'm a straight guy, and the other alum took some time away to finish a graduate degree and then is now back in town. I'm a lawyer, and I gave her some guidance on negotiating her employment agreement for a new and very high-paying job that she got, although she paid another lawyer to do most of the work.

She emailed me to say, "I'm back in town and wondered if you want to catch up sometime." I said sure, and then she emailed to set up dinner at a nice restaurant nearby soon.

So...

Is this a date?

Is this a thank-you for the legal guidance I gave, with her paying?

Or is this just two friends catching up?

She's nice, although I don't know her well. Usually I'd think that a drink at our university club would probably be more normal for a first get-together among friends.

Thanks.