She took her friend's help for granted and felt no gratitude at all.
Literal
She [topic-は] friend [possessive-の] help [object-を] natural thing [quotative-と] considering, completely grateful feeling [subject-が] did-not-exist.
当然のことと考えていて ('considering it a matter of course') explains her mindset. 全く感謝する気持ちがなかった emphatically denies any gratitude. The sentence describes entitlement — a useful word in discussing personality.