The former Liverpool footballer and I'm A Celebrity star, 41, has been romancing Newman since 2006. They already have one daughter together and are expecting their second child in the summer.
"I'm so happy to finally be engaged. Razor and I care a lot for each other," the model told The Sun
"We are expecting our second child in August so it just feels so right and like we are becoming a proper family. He could have proposed to me in a chip shop and I would have said yes.
"He has changed a lot over the past few years and we are getting on great. I love him a lot and can't wait to spend the rest of my life with him as man and wife."
Ruddock and Newman appeared on Celebrity Wife Swap together in 2007, alongside Pete Burns and his partner Michael Simpson.