Singer John Legend, Chrissy Teigen welcome baby girl

LOS ANGELES -- A Legend has arrived.

Model Chrissy Teigen and Grammy-winning singer John Legend announced the arrival of their baby girl on Instagram Sunday.

"She's here! Luna Simone Stephens, we are so in love with you! And sleepy. Very sleepy," Teigen, 30, wrote.

The couple has yet to share many details about her birth, only saying Luna was born 6 pounds and 11 ounces.

This is the first child for the couple. The "All of Me" singer-songwriter and "FABlife" co-host have been married since 2013.

Teigen was open about her struggle to conceive. On her daytime talk show, the model spoke about her struggle to get pregnant during an emotional discussion.

"I will say, honestly, John and I were having trouble," Teigen confessed. "We would have kids five, six years ago if it'd happened. But my gosh, it's been a process!"

ABC News contributed to this report