Has she ever been checked out by a doctor regarding this? There are some diseases that cause skin to be bruised easily. Has she always been like this or has it developed recently? It could just be that's the way her body works!

She should probably talk to a doctor about it. It could be just one of those things and mean nothing, but there are many other reasons this could be happening. It could be a skin malady, but could also be a bleeding disorder (women can have bleeding disorders., most notably Hemophilia C and Von Willebrand's Disease), or something indicating cancers or a large number of other things.

Probably just ask a doctor. Check what you've got so you know what you're dealing with.