And then, on her return home she found Edward had confiscated her lands, taken over her house, put her staff in jail and given custody of her children to her political enemies.
To be fair, her children were tiny-headed monsters.
Isabella went to France to regroup. And by "regroup" we mean raise a navy and an army and nab her own boyfriend, because why should Edward have all the fun? In 1326, Isa-rebella and her army sneaked over to England, where they were joined by multiple factions who were also pissed at Edward and his boyfriend, Hugh. Edward and Hugh saw the jig was up, so they fled. Within weeks they were both arrested and brought back to Isabella.