What is wrong with people?

So...here's my first blog and I'm already complaining! I decided I needed something to keep me busy between lulls at work (lately there have been a lot) and I can't afford therapy anymore so you people will have to tolerate my neurosis.
I am really irritated that a couple of my friends have insinuated that my mother is anything less that virtuous. My mom is recently divorced and dating one man....ONE! May I add only after 2 years of her initial separation from my stepfather of 15 years. My mom has joined a single's group and is having the time of her life. She is a gorgeous, vivrant, prayerful woman; and at 57 is finally being free, herself. She helps everyone who comes her way, including risking her own life (and giving my sister and me ulcers) by housing a friend who is a battered woman in an abusive 20 year marriage.
So my mom has this party at her house and she and her friends are belly dancing (she is Greek/Sicilian and has a Syrian male friend and they decided to acculturate some of their Anglo homiez) and the Syrian guy suggests they should raise money for the battered woman friend living with my mom, so they dance and raise $85. It's not a lot of money, but as you can see my mom has no problem expressing herself through dance and culture all the while promoting social justice/feminism...her way. So I tell my friend about it who by the way has ISSUES with her own mom and she says (snide tone)
"If that were in a different place what would you call it? I mean, dancing and getting money?" I say "She wasn't stripping! She was belly dancing...it happens in a lot of places and it's not stripping!" What the HELL would possess someone to insinuate that my mom is a stripper and why would you say it to ME? I am a grown woman, 28 years old...we are not on the playground telling mama jokes anymore...this really bothers me! I don't share things like that with my friends for them to turn around and insult my family. My mom may be a lot of things, but a stripper she is not. I am and always will be very protective of her...throughout most of my life I have been the adult in the relationship...including now. I am trying to let her do what she wants and not offer up my opinion about what she is doing with her life. She is picking up where she left of in her adolescence so I am getting a lot of the lines I used as a 16 year old thrown back in my face...the only way we are going to get even close to her becoming the adult in the relationship is to let her make her own decisions, express herself, and live her life the way she wants. I know this sounds weird, but it's what happens sometimes....
I don't know how to approach my friend about this, but I'm sure I'll find the words. I don't like to cause unrest in my friendships, but I woke up with this on my mind so I know it's going to bug me until I resolve it.