。
She sews with a threaded needle.
Literal
She [topic-は] thread [object-を] passed-through needle [with-で] sews.
A neat illustration of Japanese pre-nominal modification: the relative clause 糸を通した ('that has been threaded,' literally 'through which thread has been passed') sits before 針 ('needle'), with no relative pronoun connecting them — Japanese threads modifiers in front of the noun and lets the listener parse the gap. The whole noun phrase 糸を通した針 is then taken with で in its instrumental sense ('with / using'). 糸を通す is the standard collocation for threading a needle.