Sienna Miller and Tom Sturridge were low-key yesterday while out for a walk in NYC. The couple went for a stroll without their baby daughter, Marlowe Sturridge, who entered the world in early July. Sienna, Tom, and Marlowe were in Italy last month for the little one's first-ever vacation. The end of the year will be full of travel for the family, since both Sienna and Tom have movies to promote. His On the Road arrives in theaters Dec. 21, while Sienna's The Girl, in which she plays Tippi Hedren opposite Toby Jones as Alfred Hitchcock, airs on HBO Oct. 20. During an interview Sienna granted while in Italy, she spoke about the challenges playing a real person. She said, "I went to meet the real Tippi to help understand the role, and found that under the cool Scandinavian exterior she's a warm and maternal figure. . . . It was a physically demanding shoot. I was in my first trimester, throwing up a lot. One of the great challenges was maintaining Tippi's stoicism."