Mischa Bartons younger and troubled sister has checked herself into rehab for her dependency to pain killers. Celebrity Babylon is reporting that Hania Barton who just turned 19 was getting "out of control".

So how is her older sis taking it? Naturally, like any caring family member she is very upset with what's going on with her lil sis. However, she is glad that she is taking action and getting help.

"Everyone is hoping that this will be the first and last time Hania has to be in rehab," says the family source, "she's young, but she's a smart girl, she will be fine."

We wish Hania well!