Joanna has some of the best boxing in MMA, she's slick and has power. Awesome jabbing skills, jabs to the body, hooks, uppercuts, etc. Has a good teep also. She tends to get into brawlings tho.
If the fight should happen, Jojo would need to establish her teep right away and start kicking the legs of Jedi's to take away some of her power, so she can sit on her punches as well. Jojo could also user hellbows when Jey wants to close the distance and then clinch, Jojo's knees and elbows would do the trick, using takedowns to mix up and set other attacks would also be useful.
Jojo's gotta be careful and use more headmovement and footwork (like she did against Katja, Cummins), kick the arms, so to tire and hurt Jey's arms. Also, most of Jey's money shots come from that right hand, specially her slapping overhand right, Jojo needs to take away the jab of Joanna so that she can't set it up.
Both have good chances of winning, Joanne's got more tools in the standup and she has shown she's very proficient in all areas of the striking game. Joanna's very atheltic, strong chick that's very explosive and has good cardio, with KO power. It would be an awesome matchup.