wow did this bring back the memories! lol. defanitly got a good laugh thinking of it.
my oldest (3 at the time) did this to my 3 month old son. it was right after halloween and he was dressing them up to go trick or treating. it was all over his face and hands! the only thing i used was soap and water and with in a couple of days it faded. hopefully others have found something to take it off right away, so she doesn't have to explain to everyone why its all over her. but for most when they seen the two kids together the mom's would laugh and say i remember that happening to me also! the joys of motherhood.
what ever you do DO NOT use the magic eraser on the little one! it will cause chemical burns! it even says it right on the package it comes in.
good luck with it! she will have to let you know what worked best.. now that i have two little ones again, i can see it happening once again and i will know what worked best!