Can my ex claim our daughters child care expenses even if I am the one claiming her as a dependent on my return and she's claiming our son who didn't go to daycare?

Legally divorced with 2 kids. Our divorce decree states I claim our daughter, she claims our son. However, I was custodial parent more than 1/2 the yr, then per the courts, my ex became custodial parent for the remainder of the year (5 mths). In which then our daughter started attending daycare that my ex paid for.