Jennifer Aniston says that playing mother to a dog in Marley & Me was a dry-run for the real thing.

The actress – who turned 40 this week – still sees having children as part of her future, and embraced her role as a surrogate mum to an unruly labrador as an opportunity to explore the idea.

Jennifer tells the Daily Telegraph, "I want to have children. That's my plan."

There have been reports that the former Friends star feels under pressure to start a family after ex-husband went on to have six kids with Angelina Jolie following their 2005 divorce.

Whether Jen's current beau John Mayer is ideal daddy material remains to be seen...

 See why Jen is still fabulous at 40 below