Lindsay Lohan strolls hand in hand with her lesbian lover as friends say she's finally happy

The actress was spotted holding hands with her girlfriend while taking a break from shooting her new film project, Labor Pains.

She didn't hide her affection for the DJ, who has become a regular visitor to her LA set in recent weeks, grabbing her arm as they made their way through a crowd of onlookers.

Visitor: Samantha Ronson catches up with Lindsay Lohan as she takes a break from shooting Labor Pains in Los Angeles

Getting to grips: The couple were spotted holding hands as they made their way through the crowd

The pair have been keeping company for over a year, but first went public with their relationship during a visit to Cannes in May, where they were spotted kissing aboard P Diddy's yacht.

Friends say the couple are 'both really happy,' adding that Lindsay 'feels safe' with Samantha, who is the sister of music producer Mark Ronson.

Meanwhile, Lindsay's family life is getting even more complicated with news she may have a half-sister.

Her father is addressing a woman's recent claim that she had a daughter by him 13 years ago after calling a press conference on Friday.

Mr Lohan was joined by his girlfriend Erin Muller at the event, which also served as a launch party for the online comedy series Wannabeme.tv, which co-stars Michael Lohan.

'If I wasn't Lindsay's dad or Michael Lohan, this wouldn't be getting any attention,' he said.

Mr Lohan said he once had a relationship with a woman named Kristi Horn and that he had not seen her in 12 years.

He said the two were seeing each other while he was separated from Dina Lohan, and the woman was going through a divorce.

Mr Lohan said he learned of the claim after receiving letters from the woman and photos of the girl purported to be his daughter when he was incarcerated.

'While I was prison, I got a letter, and she said that she had a paternity test with her ex-husband,' said Mr Lohan, who has hired lawyers to look into the claim.

'The results were negative with him, and she felt that I was the father. I said, "Well, why did you wait so long to tell me?" She said there were a lot of things going on in her life.'

Mr Lohan said he has not spoken with Lindsay or any of his other three children about it. He said there was a resemblance in the photos of the girl to his daughters.

Lohan, a former Wall Street broker, married Donata 'Dina' Sullivan in 1985.

They settled a long-simmering divorce in August, though they returned to court in New York earlier this month over custody issues. He was released from prison in March 2007 after serving nearly two years for attempted assault and driving while intoxicated.

Mr Lohan complained that Dina was not adhering to a visitation agreement involving their two youngest children, Ali, 14, and Cody, 12.

The children live with their mother in the town of Merrick, and are featured on the E! reality show Living Lohan, along with 20-year-old brother Michael.

'I haven't spoke to them,' Michael Lohan said. 'I'm not going to do it over the phone.'

Lindsay's publicist Leslie Sloane-Zelnik did not immediately return calls.