Sometimes it can be color transfer from a pair of shoes as well. I know after a photo shoot one time I had dark soles from the black suede lining of my 6inch heels.
Oh I hate that... it can take a few days to come off!
Becky is right it can happen to anyone, when you step out of the shower the first thing you put on isn't your shoes, so you are generally barefoot for sometime. Many clients will wear shoes into the bathroom and that will track salt, sand, dirt (how many condo's are near construction sites) into the suite and fresh from the shower wet feet can pick up that dirt in a very short time. It's an honest oversight, something that when she's rushing to get everything else ready she may forget to double check.
I understand that at many incalls the suites are shared and that leaving your personal belongings at the main door isn't ideal but it might help during winter months if clients were to slip off their outdoor footwear at the main door then carry them to where they'd want to store them, that would help reduce the amount of salt and grime on the floors so the ladies don't have to worry about getting their feet so dirty.. especially when they run to get that much needed glass of water for you. :-}
Oh and Lou a mirror and a little flexibility means she'll see the bottom of her own feet in many different ways, just remind her to point those toes it always looks a little more feminine and lengthens the leg.
