Weddingbee boards

My future sister-in-law is a make-up-artist. When we told her that we were engaged she asked if she could do my make-up. Of course, I said yes. (but I'm not sure if she meant for free or not.) Do you think I can ask her to do my and my mom's make-up as a wedding gift to me and my fiance? Furthermore, could I even ask her to do my, my mom's and my three bridesmaid's make-up as a gift and tell her that she can take photos of us for her portfolio. When asking to do the bridesmaid's make-up should I offer to pay for supplies? We are on a budget and she is my fiance's big sister. I would really appreciate some help on this.