。
She came to live with her aunt.
Literal
She [topic-は] aunt [with-と] live [came to-ようになった].
~ようになった marks the transition to a new living arrangement — she didn't always live with her aunt, but at some point that changed. This is a natural use of ~ようになる for life changes that happen gradually or as the result of circumstances. 暮らす (to live/make a living) is slightly warmer and more domestic than the neutral 住む (to reside).