Carly really didn't feel like she fit in with the Murphy's and was always missing her mom. She would also skip school.
Her mom and her got in an argument because her mom found out that Carly was living with such a perfect family and started to miss her and wants her back. Now Carly doesn't know if she should stay with the Murphy's or if she should go back to her mom.
Carly choose to leave back with her mom and she always remembered no matter how much the Murphy's loved her she was never one of the Murphy's.