Call her.
Be brief, unless she leads on conversation.
Don't be pushy, and leave her space to say no.
"Hello, my name is <XXXX>, and we were introduced by <XXXX>. We talked a bit and I was wondering if you'd like to get some coffee together, there's this great place in <XXXX>. What do you think of the idea?"
Remember, if she says no, "I don't have time"... do not insist. Get over it move on.
Good luck!