Ashlee Simpson and son Bronx on June 12, 2011 in Los Angeles, California. Credit: Alexandra Wyman/

Weeks after her sister Jessica Simpson welcomed her daughter Maxwell Drew Johnson into the world, Ashlee Simpson wanted to expand her own brood. So she buckled down and got son Bronx, 3, a furry, four-legged sibling!

"BX and our new pup snuggle fest!" she Tweeted along with a pic of her son with ex-husband Pete Wentz and a pint-sized blonde French Bulldog puppy, both of whom are swaddled in cozy blankets.

On May 1, Ashlee, 27, became an aunt when Maxwell (Jessica's first child with fiance Eric Johnson) joined the Simpson brood. The morning of the little one's birth, both families had breakfast together and made Starbucks runs.

"Maxwell is so precious and peaceful," Ashlee and Jessica's mom Tina was overheard saying while getting her java fix.

"We are so grateful for all the love, support, and prayers we have received," Jessica wrote that day on her website. "This has been the greatest experience of our lives!"