。
She can make her own clothes by herself.
Literal
She [topic-は] her own clothes [contrast-は] [by-oneself-自分で] make [thing-事-が] able.
自分 appears twice in different roles: 自分の (possessive 'her own') and 自分で (the adverbial 'by oneself, on one's own'). 自分で specifically marks self-action — done without help. The contrastive は after 自分の服 sets up an implicit contrast: 'her own clothes — those she can make herself,' implying that other things might require help. ~事ができる is the formal potential pattern; here 事 is written in kanji rather than the more typical kana こと.