how do I deal with that when we meet in person since I have a good indication that she probably doesn't want much more than just an aquanticeship and silly me thought we could be friends. Or am I in a mood and reading too much into this and maybe need to just take a step back?
Yes, I think you were very politely "blown off". It could be for any number of reasons that have nothing to do with you as a person, or the acquaintance might not feel the same potential friendship you do.
Either way, you deal with it by being polite, cordial and professional when you meet in the future. You don't need to refer to your declined invitation, just deal with the business at hand. You don't mention what types of professional settings, but whatever the context, simply provide the information/services and exchange greetings. She may continue to chat with you at the same level as before (you don't mention how often/long you had interacted previously), or she may not.
It's no fun when someone doesn't want the same level of friendship that we do, but it happens.
