。
She was anxiously trying to find some way to get revenge.
Literal
She [topic-は] somehow-doing revenge let's-do [quotative-と] was-impatient.
焦る (あせる) is a particularly Japanese verb meaning 'to feel impatient, anxious, or hurried — restless to act.' It captures the inner agitation of being unable to wait, mixed with worry that things may not turn out. Combined with the volitional 復讐しようと ('trying to take revenge'), it paints a picture of barely-contained impatience. The volitional+と structure ([volitional]+と + verb) is one of the standard ways to mark intention or attempt — the と here is quotative, framing the volitional clause as the content of her drive. なんとかして adds the 'by hook or by crook' note.