So she has bruises. Okay. The question is who put them there.
This picture taken JUST BEFORE she is grabbed. So the other reporter (plaid shirt) and the Secret Service Agent directly behind Trump are between Lewandowski and Fields.
How did Lewandowski grab her?
Looks more likely that it was the Secret Service agent who grabbed her as she reached toward a Presidential Candidate with some kind of object, probably a pen, in her hand.