Lindsay Lohan's father didn't tell her she has a half-sister.

A recent DNA test has proved Michael Lohan fathered 17-year-old Ashley Horn after a fling with Kristi Horn while he was still married to Lindsay's mother Dina but the 'Liz & Dick' star was surprised to hear the news during an appearance on 'Good Morning America'.

She said: ''I didn't even hear that, so thanks for the news. I don't pay attention to any of it. I can't. I don't really want to get into that because I want to stay on the positive side of things.''

After a tumultuous few years for the actress including spending time in jail and rehab and falling out with both of her parents, Lindsay insists her life is now back on track.

She said: ''I'm in a great placeI just want to move forward.

''Everyone goes through things in life but everything happens for a reason, good or bad.''

Lindsay, 26, recently finished work on 'The Canyons' and is constantly looking for more roles.

She explained: ''I'm reading scripts every day. I keep calling my agents. I'm like, 'Just keep me on set. It's safer that way'.''