She said: "It's good my family and my parents have finally let go of the leash."
Katy's mother previously expressed her concern over Russell's past, urging him to "go towards the light" and find God.
Mary said: "Russell must go towards the light and not toward the darkness. Only God can take the very worst person and turn them around for good.
"You just have to see how the Lord's will is done. I mean, how many times have your kids disappointed you so profoundly you wanted to get up from the chair and knock them out?"
However, following the couple's wedding last October, Keith admitted he couldn't wish for a "better son-in-law".
He explained: "I could not have wished for a better son-in-law in Russell. He makes my girl so happy. She's so happy and he makes her light up. They're going to be just fine.
"You couldn't see two f***ing happier people."