。
She's youthful as ever.
Literal
She [topic-は] as-usual is-youthful.
若々しい ('youthful, young-looking') is built from 若い ('young') reduplicated with ~々 — the iteration mark — and the ~しい suffix for 'having the quality of.' This pattern of reduplication + しい is productive: 弱々しい ('weak-looking'), 痛々しい ('painful-to-see'), 騒々しい ('noisy'). The implication is often visible 'X-ness' — observable rather than internal.