Hi! ^_^;
I'm new too and live in the US! Being from America, I can see why she might find it offensive. It's not a word I would use, only because of how some people choose to use it. (some things that sound innocent can soundreally ugly when said with ugly intensions.) I'm hispanic and would never use the S word... just cuz it has too amny negative associations with it.
As long as you're not doing to insult anyone, I don't see the harm in it tho... it's your choice.
Lizh <3