"Eric got carried away with his swaddling skills!" the 'Fashion Star' mentor, 32, wrote on the micro-blogging site.
The tweet was accompanied by a funny picture of her mother, Tina Simpson, wrapped up like a baby in a beige blanket, reported Us magazine.
Prior to posting the photo, Simpson had not tweeted anything since June 22, a full week before she delivered her son Ace Knute Johnson. The mother of two broke the news of Ace's birth on June 30.