Katie Holmes was feeling incredibly proud on Sunday as she marked her only daughter's 15th birthday.The Dawson's Creek star is a doting mum to Suri Cruise and made sure that the teenager's big day was extra special.MORE: Katie Holmes looks identical to daughter Suri in ageless throwback photo Katie shares Suri with ex-husband Tom Cruise, and the teen lives in New York with her mum. VIDEO: Katie Holmes shares sweet video of daughter Suri in New YorkWhile the actress has worked hard to keep Suri