Ex father of daughter took daughter as a dependent on 2020 tax return and received the $1,500 advance child tax credit.  For 2021 mother is taking the daughter as a dependent along with her son.  She received the $1,500 advance tax credit for him.  For the tax Form 8812 Pro Series she is receiving a $3,000 tax credit for the daughter.  How do I show that she should only receive tax credit for her daughter?