Miley Cyrus Has Given up Partying for Relationship With Liam Hemsworth

Miley Cyrus has a lot to be happy about.

The singer, 23, is back with her on-again fiancé Liam Hemsworth, 26, and scored a role as a new coach on the NBC hit, The Voice.

"Miley is a changed person, and she actually seems to enjoy it," a source close to the star revealed to PEOPLE.

The source talked about the rekindled romance between Liam and Miley and said, "it seemed she was just making changes to please him."

"Miley is doing yoga and seems very healthy," says the source. "She rarely parties and is taking better care of herself." She seems "very happy" living a more low-key life.

According to the source, the couple lives in adjacent homes in Malibu.

"With Liam back in her life, she seems to enjoy it much more," adds the source.