Sienna Miller tackles daughter's head lice

Actress Sienna Miller had to tackle every parent's worst nightmare recently, when her daughter came home from school with head lice.

The British beauty, who relocated to New York City earlier this year (16), reveals four-year-old Marlowe is always attracting germs, and when she complained about an itchy head, Sienna instantly knew what the problem was.

"She got nits for the first time - like head lice," the 34-year-old told People.com. "She's like a Petri dish of germs. She just brings home things from school. It's the joy of having a child in school."

"She said, 'I've got ants in my head'," Sienna laughed, "and I was like, 'Oh no!' I knew exactly what it was."

The American Sniper star headed straight for a local pharmacy to pick up medicated shampoo and promptly took care of the issue.

"We dealt with it," she said. "We had the hair fairies over."

Sienna, who split from Marlowe's father, actor Tom Sturridge last year (15), is thankful to have cleaned up the lice problem so easily, because mom and daughter are now gearing up to head back to the U.K. for the festive season.

"We're gonna be in England," she shared. "We're gonna be snuggled up with old movies and fireplaces, and mama's gonna have some wine. Gonna stuff our faces with turkey and food, like we do every year, and try not to squabble as a family."

It's not clear if Sienna's rumored new boyfriend, director Bennett Miller, will be joining the actress and her daughter for the holidays. The stars, who worked together on 2014's Foxcatcher, reportedly began dating earlier this year (16) after dancing together at the Met Gala afterparty in New York in May (16), and attending the Wimbledon tennis championships in London in July (16). They were also spotted together at the U.S. Open tennis tournament in the Big Apple in September (16).