It doesn't matter who's lying or telling the truth. When Pac got her to record the song and take the pictures, the damage was done. I don't think he cared whether he slept with her or not. The intent was to make it appear that he did. I don't even think it was done to make Big mad. It was done to clown Biggie and cripple his credibility as a "playa". The picture is in magazines and the streets are loudly echoing that Pac slept with Biggie's wife. That doesn't look good especially when he had singles like "Big Poppa" and "One More Chance".
The fact that she's still talking about it just adds more power to something that was put into action nearly 20 years ago. At this point, it should be a non-factor, but she's making more out of it than it was. She's damaging her own cred by continuing to talk about it.
She definitely caught it though because if I'm not mistaken, Junior M.A.F.I.A.'s "Get Money" video is a diss to her. On top of it, both of Biggie's mistresses are in the video.