Ryan Cabrera and Ashlee Simpson
Jeff Frank/ZUMA; Jamie McCarthy/WireImage
08/30/2008 at 06:00 PM EDT
Ryan Cabrera rarely sees his former flame Ashlee Simpson
these days, but he saw enough in their relationship that he doesn't doubt her parenting ability.
"She'll be a great mom," the singer told PEOPLE Friday at the opening of Yellowtail Sushi Restaurant in Las Vegas.
Cabrera, who dated Simpson in 2004 and was reportedly the subject of her song "Pieces of Me", said, "She's just a good person and she's dedicated to her family."
Recently Simpson, 23, said she and husband Pete Wentz, 29, have been busy baby-proofing the house
and getting a nursery together. None of this surprises Cabrera about the couple.
"It's a good family. It will be a good home."
In a recent posting on her blog
, Simpson denied the Internet rumor that she cried and went shopping for size 0 jeans after her doctor told her she'd gained too much weight. "1. My doctor says I am right on target with my weight gain. 2. Have not been to Planet Blue in at least two years. 3. Love my maternity jeans ... they have stretchy tops it is awesome!" the singer writes.
"Carrying a child is the most inspiring, emotional, amazing experience of my life," Simpson continues. "My weight and my pant size are the absolute last thing I am concerned about. I am only concerned with having a healthy pregnancy and a healthy baby. People who talk and judge pregnant women's weight need to get a life!!!"