Molly Perkawitz

Biography
Molly left Morgan after she found out about his affair with another woman named, Paris, and she took Megan and Liz and told him to take "good" care of Jenna all by yourself.

Later in season 3,

Molly returns with Megan and Liz and she wanted to be a family again but, Morgan refused and she left him again.

In Season 6

Molly returns and makes a surpising news that changed Andrea and Jenna's lives forever.

Solos
Season 5:

Duets
Season 6: