、。
She rescued her drowning children.
Literal
She [topic-は] her own children [subject-が] drown [nominalizer-の] [object-を] rescued.
~のを + verb of perception/action with 救う means 'rescued (someone) from doing X.' 自分の子供達が溺れるのを救った reads 'rescued her children from drowning' — の nominalizes the embedded clause 'her children drown,' and を marks it as the object of 救った. 達 (or たち) pluralizes 子供, signaling more than one child. The mid-sentence comma creates a small narrative pause before the verb, lending weight to the rescue.