。
She just couldn't bring herself to take in a child and raise one.
Literal
She [topic-は] no-matter-what child [object-を] receive [then-て] raise mood [contrast-は] could-not-become.
気になれない is the canonical Japanese way to say 'I can't bring myself to' — literally 'cannot become in the mood.' The contrastive は in 気にはなれなかった (instead of plain 気になれなかった) sharpens the rejection: 'as for the mindset to do that, no, that didn't happen.' 子供をもらって育てる ('receive a child and raise (one)') is the gentle, slightly old-fashioned phrasing for adoption — もらう ('receive') frames the child as something gratefully accepted from another family. The combination of どうしても + couldn't here flips どうしても's usual 'no matter what' assertion into 'no matter how (I tried), I couldn't.'