Country star Garth Brooks' daughters terrified his wife Trisha Yearwood when they first met - because she had no idea what to do with three young girls. The singer, who wed Brooks in 2005, got an instant family when she started dating the superstar, who had three daughters from his first marriage to his childhood sweetheart. And she admits she had no idea how to play 'mum' with the girls. She reveals, "It (was) scary. I'm madly in love with this guy, and this is the deal. So, I was really scared of them at first. "We would have them every other day, so they would go to their mom's at 6 o'clock, and I would be sitting there thinking, 'What do we do until 6 o'clock? I don't know what to do with children.'" She admits that now she's the girls' stepmother, she's still nervous about spending time with them, but Brooks' daughters have helped to make sure she feels like part of the family. She adds, "It became, 'OK, I'm still scared, but it's not as bad,' and then it became, 'I love having them all the time.' You fall in love with them. You learn why people have kids." Yearwood insists she hasn't tried to become a replacement mum or the girls' best friend: "I'm just like a bonus mom."