Katie Holmes has promised Tom Cruise another baby - after he marries her.The 'Batman Begins' actress - who gave birth to the couple's first daughter, Suri, in April - has reportedly promised to make her fiancé's dream of another baby come true as soon as he makes her his wife.A source told the National Enquirer magazine: "She loves being a mum and can't wait to do it again. But first, she wants to be Tom's wife - so they've made a pact."The couple's wedding, which was rumoured to be taking place this autumn, is now reportedly being fast-tracked because the former 'Dawson's Creek' star is hoping to get pregnant again by the end of the year.The source added: "Tom's always intended to make Katie his wife, but other things kept getting in the way. Now, the thought of becoming a biological father for the second time has put their wedding on the front burner."Tom already has two adopted children, Isabella and Connor, from his marriage to ex-wife Nicole Kidman.