One down, one to go!

It looks like Sean Penn's daughter, Dylan Penn, has given the stamp approval to her dad's girlfriend, Charlize Theron. During an interview with US Weekly at the DT Model Management 2-Year Anniversary Party in West Hollywood last Thursday, the 23-year-old gave her thoughts on her father's relationship with the actress.

"They're a great couple. They're both very happy and yeah, I love it," the model said. "They're both extremely strong personalities and they're very intelligent so conversation lasts between them."

So could they we really be hearing wedding bells soon? Last week, the South African beauty, 38, sparked rumors that she and Penn, 53, were already engaged when she was photographed wearing a $4,900 Anita Ko Leaf Ring in L.A. But this was abruptly denied when Theron said she bought the ring herself.

Even Dylan Penn was not aware of any plans to marry. "I heard that rumor," she said. "I don't even know. I have no idea."

But when asked if she would be welcome to the idea of the Snow White and the Hunstman actress becoming Mrs. Penn, Dylan had nothing but good words to say. "Always. Sure, why not?" she said. "If it's meant to be."

Dylan even says there's room for possible half siblings in the brood, if ever Theron wants to have children with her dad. "Always," she agreed. "The more the merrier." (Sean has two children with House of Cards actress Robin Wright, Dylan and Hopper, 20. Meanwhile, Theron has a two-year-od son, Jackson, whom she adopted in 2012)

And even if the engagement rumors aren't true, Dylan's father and the Prometheus actress might still be tying the knot in South Africa come summer, and possibly planning to expand the family, as well. "Sean is revitalized with Charlize," reports US Weekly. "They want to get married soon."