The former glamour model - who has son Junior, five, and three-year-old daughter Princess Tiaamii with the Australian hunk, as well as eight-year-old Harvey from a previous relationship - admits she has struggled with parenting the children since splitting from the singer last year and wishes he had backed her in the face of criticism.
She said: "I'm not going to lie and say it's been easy. If I'm pictured with the kids out it's, 'She's using the kids', if I'm not pictured with the kids it's, 'She's never with the kids.'
"There is one person who should have defended me and hasn't and has milked it all the way - Pete. All he had to say was, 'She's the mother of my kids, leave her alone, she doesn't deserve this.' Instead he's milked it and that's really hurtful."
The 32-year-old star - who recently had her marriage to cage fighter Alex Reid blessed after the pair wed in a surprise ceremony in Las Vegas in February - admitted she finds it hard to let her guard down to the public, as she always feels she needs to defend herself.
She added in an interview with The Sun newspaper: "Alex always says to me that I have such a hard exterior, people don't see the soft side of me. He encourages me to show that, but I can't let my guard down because I'm used to having to defend myself."