。
She has her hands full with the kids.
Literal
She [topic-は] child [target-に] hand [object-を] is-burning.
A vivid Japanese idiom: 手を焼く literally means 'to burn one's hand,' used metaphorically when someone is so troublesome you don't know what to do with them. The hand-burning image suggests singed fingers from grabbing something too hot to hold — a perfect metaphor for dealing with kids you can't quite manage. The progressive ~ている locks in 'is currently in this state,' so this isn't a one-off frustration but the daily-grind feel of perpetual difficulty.