。
She's a richly talented painter.
Literal
She [topic-は] talent rich [attributive-な] painter [is-さ].
豊か ('abundant, rich') is a な-adjective; here it forms the compound 才能豊か ('rich in talent') by attaching directly to 才能, then the resulting expression takes な to modify 画家 ('painter'). The sentence-final さ is a casual masculine particle that closes a statement with relaxed conviction — softer than よ, more declarative than ね. It often sits at the end of a definitive opinion or characterization. 画家 specifically denotes a visual artist; 芸術家 covers any artist more broadly.