Getting out of the Friendszone is a gotdamned near impossible process. It takes time, energy, effort, non-effort, dating other women and being as on top of your game as is mentally/physically possible.
IF there is or was a physical attraction, this works in your favor, even if she "put your ass in the LJBF Zone"
You need to date other women, and flaunt them in front of her. Lets say she likes to hang out at "O'Brien's Pub" You need to take an interested date there, introduce them, and then tongue your date in her face.
REFUSE to be an emotional tampon. Hang up, or tell her flat out you arent interested in how miserable she is without him, or how much of an a$$hole he was, tell her to tell that to her little girlfriends.
Keep the contact/communication open, but vague and sporadic, go 4 weeks without contact, then a quick phone call, ect.
Fukk with her mind about being "Just Friends"...."I'm going to Vegas next week" (This is a week when she has her kid, and is bored stiff) IF you were my girl, you'd be going too!! Oh well". Then, you photo text her from the pool at the MGM Grand "Weather is here, wish you were beautiful"
And so on.