Orthodontist or Weight Loss Clinic?

I took my DD to her orthodontist today to get the molds of her teeth and such. I got up to the counter and the lady behind the counter takes a copy of my insurance card since I forgot it last time. She says "Can I ask you a personal question and you won't get offended?" My standard answer to that is "well, that depends". Here's how the rest of it goes:

Her: Well, I wondered if you are taking any kind of medication.

Me: I asked what she meant.

Her: Well, like, do you take anything for.................thyroid or anything?

Me: Yes, I do.

Her: Does it make you puffy? Well I ask because a girlfriend of mine takes it, but SHE is skinny, but she takes it and if she misses a day, she gets puffy. I just wanted to know if that happens to you.

Me: Ah well, you're not supposed to skip days, and I've never noticed that when I ever did.

Her: Oh, I ask you because she also sells diet pills that really work. I think they are herbal or something. I took them and I lost like 22 pounds in a month and I've kept it off.

Me: Oh really? And then I grabbed my insurance card from her hand and went to sit in the waiting area with my daughter. Of course, I was at a total loss for words and did not show that I wanted to throttle this woman.

Her: Oh, I hope I didn't offend you, sorry if I did.

Me: Oh gosh, you're fine.

Why did I say it was fine? I was also so angry that I probably would have cried had I actually addressed it.