Can that be done even if the complaint by the woman doesn't involve any federal laws?
Yep. She isn't going to sue anyone. No attorney is going to take her case on a contingency. The families of the two players have enough money to bankrupt any attorney would would try. Besides, the players are going to get plenty of money from others who are liable. A judge would throw out any complaint she might file and sanction her attorney for filing a frivolous complaint.