Article continues below advertisementSia is pushing back after headlines spotlighted her $42,500-per-month child support agreement, offering a candid explanation for why she agreed to the deal, and what the past year has cost her."I'm a sober working mom trying to buy peace," the singer wrote on X after the terms surfaced. "I have primary custody of our son and since i am the only parent earning income i still have to pay California's incredibly high child support.