"She's laughing, playing and drooling on everything," Michelle says.
Josie, who was born at only 25 weeks on Dec. 10 via emergency C-section, weighed only 1 lb., 6 oz., at birth. She now weighs 15 lbs., and is thriving at 11 months old.
"We see the hand of God and the answer to all our prayers in how well she's doing," Jim Bob says.
Though she's still on oxygen at night when she sleeps, Josie is otherwise developing normally and "sailed through her last check-up," says Michelle, who appears on TLC's 19 Kids & Counting.
And Michelle's love doesn't end with her own 19 kids: Her daughter-in-law Anna, who is expecting her second child describes her as an "amazing" grandmother.
"I thought with so many children, and everything she's gone through with Josie, she wouldn't have a lot of time," says Anna. "But she is an amazing grandma and it is so cute to see her be a mom to older children, little children and a grandma, too."
"Mackynzie was going to be really spoiled being the only grandchild," Anna says, "so it's great there's another one on the way."