Sienna Miller, Tom Sturridge expecting first child
"Friends are really happy with her relationship with Tom," a source tells Us, adding that the couple has no plans to marry. "He's younger, yes, but he's mature and he's a good guy."
Miller is 30, Sturridge, also an actor, is 26.
"They just spent the holidays in Paris together after they announced the news in London," adds the source.
Miller broke up with Jude Law, 39, (again) in February. The couple had reconciled after a 2006 split precipitated by Law's cheating on Miller with his children's nanny.