She needs to know your expectations. She wants someone with unlimited availability, in a perfect world. Not every salon considers 40 hours to be full time. There are some franchises that consider 30 hours full time. I know of one that doesn't want a stylist on the floor over 7 hours in a shift to keep them from burnout.

If you absolutely need full time let her know this. Or maybe you can make do with 20 hours a week until you can work your way into full time.

But if you only want 20 hours a week it is important you are up front with her. She has to consider hours to make out her schedule. Be truthful with what you need.