As Jay DeMarcus' baby daughter Madeline Leigh quickly approaches her four-month birthday, the Rascal Flatts bassist decided to share a family picture and to give fans a sneak peek into his home and his little girl's nursery. DeMarcus and his wife, Allison, also reveal how the first few months have been since baby was delivered via C-section on December 17.

"[Her hair] was coal black and she looked just like Jay!" Allison tells PEOPLE of Madeline Leigh. "She still does. My sister calls her Jayline!"

"Pulling away from the hospital, I just wanted to say to the nurses, ‘Are you sure about this? I don’t think either one of us is trained to do this,’" Jay adds. But it's been a few months since the DeMarcus family welcomed their baby at 37 weeks, and the proud dad says they're finally settling into a schedule. "I don’t do that as much as Ali does, she is a saint about it,” he admits. "We take turns getting up. I do late night. With my schedule, I’m up so late that I’m used to being up at 2AM."

Though it can be hard to raise a baby and be in a touring band, DeMarcus looks on the bright side. "I’m working on the road and gone a lot, so she’ll always be glad to see me! It’s like a special occasion," he gloats.

The DeMarcuses were convinced they were bringing a baby boy into the family, so when an ultrasound showed otherwise, it was Mr. DeMarcus who pocketed the "Daddy's girl" trophy. "I looked at Jay and said, ‘Well, you win.’ And he was like, ‘What do you mean?’ I said, ‘Because girls always love their Daddy to death. She’ll get mad at her mother, but Daddy can do no wrong,’" Allison says.

Might be true, but even though the new parents make it look easy, the Rascal Flatts star admits it hasn't been a total breeze. One night he was left alone with Madeline Leigh, who wouldn't stop crying no matter what tricks he tried. "That was a moment when I stared at her and thought, ‘Now what? I am not qualified! I don’t know what to do,'" he shares, adding a revelation: "'This is not a passing phase. I am responsible for this life for the rest of my life!’ It can be pretty daunting."

More photos of Madeline Leigh and the DeMarcus family -- including a peek into baby's princess nursery -- are available here.