Brothers Osborne's John Osborne and Wife Lucie Silvas Welcome Twins Arthur and Maybelle

John Osborne and Lucie Silvas officially have a family of four!

The Brothers Osborne country rocker, 40, and his singer-songwriter wife, 45, have welcomed their first babies together, Osborne confirmed on his Instagram Story Tuesday.

The couple's twins — son Arthur and daughter Maybelle— were born one minute apart on Tuesday, March 21 in Nashville.

Arthur was born first, weighing 3 lb., 13 oz. and measuring 15½ in., followed by Maybelle, who weighed 5 lbs., 1 oz. and measured 18 in.

"We did it. y'all. @luciesilvas is a damn warrior princess," the new dad proudly wrote.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

Later, he added, "Welcome to this crazy world, Arthur and Maybelle. It's going to be a wild one. Lucie - You're a damn boss."

John and his brother and bandmate TJ, 38, had to drop out of Monday night's charity Love Rising concert in Nashville after Silvas unexpectedly went into labor a little more than a month before her due date. Earlier in the day, John posted a note from the Grammy-winning duo on the band's Instagram page explaining the situation.

The couple first shared their exciting baby news with PEOPLE exclusively in November.

"It is such an amazing thing to be in this position to be growing two babies," Silva said. "When you think that you may never have the chance to have children and then suddenly you're going to have two, it's amazing."

The couple, who have been married since 2015, underwent in vitro fertilization (IVF) to conceive their babies, and hope to help others by sharing that experience publicly.

Ahead of welcoming their babies, Osborne was already confident Silvas would make an "amazing mom."

"I already know Lucie's going to be an amazing mom, because she has had to be a mom to me a couple of times, when I'm being ridiculous or I've had a few too many drinks," he joked. "She's actually inherently a very maternal person."

"I would think any of our friends would say that — when they need love and affection and a genuinely nonjudgmental person and ear to talk to, they go to Lucie, because she has a very motherly instinct already without having had kids. It's very natural," he continued. "I have no doubt in my mind that she is going to transition into motherhood as good, if not better, than anyone."

"Myself, I know I'm going to be fun, but I don't know how I'm going to take it. The verdict is out on that one! However, Lucie is going to absolutely crush it as a mom — I would bet everything I have on that."