Leighton Meester has won her court battle against her mother.

Constance Meester had claimed the pair had an oral contract guaranteeing the actress would pay her $10,000 a month in response to papers filed by the 'Gossip Girl' star in July 2011 claiming the $7,500 she sent home each month to help care for her younger brother was misused by her mother for personal reasons, such as cosmetic surgeries.

Although Constance - who countersued for $3 million in damages - dropped her court case in December, 'Gossip Girl' star Leighton pursued the legal action in order to obtain a ruling stating that she does not owe her mother parental support.

According to gossip website TMZ, Judge Gregory Alacron ruled yesterday (06.06.12) that there was no valid agreement for Leighton to pay Constance any amount of money.

Leighton is also said to be seeking custody of her 17-year-old brother Alexander, who has suffered health problems, including recently undergoing brain surgery.

A source previously said: ''Leighton is disgusted by her mother and is determined to get her brother Lex out of that situation.

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