It seems I have the same thing on my elbows more often than not. They are not realy bruises, these marks occur when your joints come into constant friction (ie crawling, kneeling, scratching).
In my younger days, I'd slide along corridors on my knees. My knees would turn red and have all sorts of marks on it.
Not saying it wasn't a bruise. But that's one explanation for those marks.
I don't particullarly want to think of why she was spending that much time on her knees.
I agree. Just, considering the situation, I have some *real* questions in mind.