。
She somehow managed to read a book written in French.
Literal
She [topic-は] French [in-で] was-written book [object-を] somehow read.
This sentence has a passive relative clause: フランス語で書かれた本 ('a book that was written in French') — the past passive 書かれた modifies 本 ('book') attributively. で here marks the medium of writing (parallel to で for 'in French' as the medium of speaking). どうにか ('somehow, with difficulty') signals that the achievement was hard-won — she struggled but pulled it off. The combination paints a satisfying small triumph in language learning.