makeup and tipping???

ok, I have a question, I am paying for me and my mom and his mom and four bridesmaids make up to be done
it is about 85 per person
do I have to tip the two girls too?? I have heard conflicting things about this some say 20% others tell me it's in the price
what am I supposed to do
what have you guys done or heard
thanks in advance
tammy
so stressing about the bar exam that I dont even know why this stupid thing crossed my mind today!!
also can someone tell me exactly how to scan
everytime I go to attach an image it never posts
I mean, I know how to scan but when i attack my pics they do not show

first off, good luck on the bar!
Second, I'd tip one price for all-combine and give one decent sized tip? Is this one person doing all the makeup or 2 people?
If its 2 people, tip each a decent amount.