Maya and Josie cannot take power, just as the MC cannot become president of the DIK, at most Josie and Maya take out Queen with the help of the MC, and they will become HOT, but Sage will be the president.
I believe that Jill is Bella's younger sister, perhaps half-sister, but not daughter.
They may not have family ties, Isabella may have grown attached to Jill by witnessing the bullying she has suffered.
I also believe that these acts could have been caused by Quinn, maybe even Jill was an aspiring HOT at one time, but Quinn knew that the girl could bring problems if she knew about drugs and prostitution, she may have used the Scavenger Hunt to attack Jill and force her to leave. Ok, this last part is perhaps a film too elaborate. Who knows...