YOu've gotten lots of answers, so I'm probably not adding much, but here's my two cents.
1. It really seems like she was planning on you doing it all along, and has manipluated you into it, and that puts my hackles up into saying no just because.
2. If you do decide to do it, go with her to make sure she gets somethign you're willing to sew and that she gets the right amounts.
3. Also make sure ahead of time that she's not going to then come back later on and say "this isn't really what I was thinking." That could get frustrating.
I've had a few people ask me about sewing something for them, and it will really depend on what it is. If it's a garment or a quick little item, I'm willing to do that if I have some amount of control. But, if they want me to alter or mend an existing item, I'm just not comfortable doing that because I don't even alter my own RTW clothes.......
So, I didn't really add much, but felt like giving my redundant opinion .
Ticia