(Cover) - EN Showbiz - Leighton Meester is reportedly so upset with her mother that she wants her younger brother Lex to move in with her.

The Gossip Girl actress has filed a lawsuit against her mother Constance alleging that money she sent home to be used to look after her sibling was instead spent by her mother to get cosmetic surgery.

Leighton alleges in the suit filed last week that she wanted the cash to go towards helping her brother who suffers from health issues.

"Leighton is disgusted by her mother and is determined to get her brother Lex out of that situation," a source told RadarOnline.

"She wants Lex to leave their mom's California home and come to live with her in New York."

The 25-year-old star is said to be fed up of her mother's lifestyle and believes she can better look after Lex who reportedly recently had brain surgery.

"Although [Constance] is healthy and physically able to work, Constance refuses to do so. Instead, Constance expects her daughter [Leighton] to support her financially," the lawsuit states.

Leighton is apparently very close to her brother and hates that "she can't be there to help him more", the insider said. (C) Cover Media