。
She worried she might wake the baby.
Literal
She [topic-は] baby [object-を] wake-might [quotative-と] worried.
起こさないかと心配した literally means 'worried whether she might wake (the baby).' The ~ないか is an indirect question form expressing concern about a negative outcome — 'what if I wake the baby?' The と links this worry to the verb 心配する (to worry). This construction captures the internal anxiety of trying not to disturb a sleeping child.