Hefner was shocked when aspiring singer Harris called off their wedding just five days before they were due to marry in June 2011.
The couple reconciled after Harris, 26, begged the 86-year-old for forgiveness in May, reported E! online.
Marquardt is thrilled for them.
"Hef has a wedding in the works again. I just hope he's happy. I'm happy for him if he's happy. And New Year's Eve is a romantic time to get married. It's a romantic holiday. A good way to start off the new year," Marquardt said.
Hefner and Harris are said to have completely resolved the problems which led to the model getting "cold feet" last year.
"I got cold feet. Over time I just saw it wasn't for me, it was all happening so fast. I actually spoke to Hef about it before I left and we both came to the decision that getting married wasn't the best for either of us," Harris said.