I'm moving on, been waiting for her to break up with him for 4 months; can i go for her friend?

Don't wait for her you have already waited long enough. Go for her friend if she gets upset she had her chance to be with you but didn't want to enough to drop her boyfriend for you. I say go for her friend and she told you to move on go ahead move on. Just use her friend though as a rebound chick.