。
She has a well-balanced figure.
Literal
She [topic-は] balance [genitive-の] taken figure [object-を] is-doing.
均斉 ('symmetry, balance, proportion') paired with とれた (past tense of 取れる, 'be taken / achieved') gives the fixed expression 均斉のとれた ('well-balanced, harmoniously proportioned'). 取れる here is the spontaneous/intransitive form of 取る — the balance is achieved as a state, not actively taken. The frame ~をしている ('do/have a [state]') applies to things one is in or is characterized by — 緑色をしている ('be green-colored'), いい体をしている ('have a good body').