The former Liberty X singer and husband Hugh Hanley asked the model to take up the role earlier this week.
"I'm sooooo happy and over the moon that @wonderwomanshel and @hughhanley have asked me to be a god mother to there baby woo forever friends (sic)," Price wrote on Twitter.
Speaking of her pregnancy, Heaton recently said: "I went through a period four months into the pregnancy when I felt really uncomfortable in my own skin and would cry about petty things. Hugh's been an amazing support, but he'd bring home my favourite cakes every day, which didn't help my body insecurities.
"One night, he brought home a slice of carrot cake and I screamed: 'Why are you trying to make me f**king fat?!' while stuffing it into my mouth. I was a crazy, hormonal bitch!"
Heaton, who is due to give birth to her daughter in five weeks, was a bridesmaid at Price's wedding to Peter Andre and introduced her to second husband Alex Reid.
Heaton and Hanley announced in July that they were expecting their first child together. They married in the Bahamas in 2010.