So can someone help me out here? What should I have done in this situation?

I took the wife and kid to eat at Joe's Crab Shack and there was a lady there making balloon animals for the different tables. She had, not one, but two big buttons that said something like "Balloons for TIPS" or "I work for TIPS." The capital "TIPS" was her work.

Anyway, we were sitting in our booth, minding our own business and I see her start walking toward us. I tried not to make eye contact because I don't have any cash for a tip. I swiped the meal -- I don't carry cash around. She gets closer and almost passes us up when she turns her head and spies (da da dum) The Kid. Immediately, she's pulling out balloons, blowing them up and twisting them into dogs and giraffes. Meanwhile, the wife and I are reading each other's lips - "I don't have any cash. Do you?" "No, I don't, don't you?" "No."

We felt really bad about that but what could we do. We weren't asking for a balloon animal, but yet she went through the sell. We felt like she deserved some money. When the sound of rubbing rubber had ceased, we thanked the lady, but that was all we could do. I wish we could have tipped or something...

So what's the proper ediquette for this kind of situation? I felt like we should have said more than thank you, but what else could we say?