Taylor and Russell Armstrong
07/15/2011 AT 07:10 PM EDT
After months of trying to save her marriage
, Real Housewives of Beverly Hills
star Taylor Armstrong has filed for divorce.
"It was a difficult decision but I have decided to file for divorce from Russell," Armstrong tells PEOPLE in an exclusive statement. "Although we have tried our best to work out our differences, I have come to the conclusion that it is in the best interest of our family that we separate."
"Together we are the proud parents of a sweet and wonderful little girl and she remains my number one priority," the statement continues. "I am sad for my marriage to come to an end, but am confident that this is the right choice for all involved."
The reality star's tumultuous relationship with husband Russell Armstrong was featured on the first season of Bravo's hit show.
The couple denied they were splitting up
as recently as May, although they admitted to undergoing couple's therapy.
"They've gone through therapy and they have issues within their marriage that they're actively working on," a source close to Armstrong told PEOPLE at the time. "They're both really committed to making their marriage work."
Armstrong, 39, and her husband, 47, were married in 2005 and are parents to daughter Kennedy, 5.