The former 'The Girls Next Door' star, who has a nine-month-old daughter, Rainbow Aurora, with her husband, Pasquale Rotella, is hoping to expand their family by the end of 2014.
The blonde beauty, who enjoyed a belated celebration at the Palms Hotel & Casino's Moon Nightclub in Las Vegas on Saturday night (28.12.13), after turning 34 last Monday (23.12.13), told UsMagazine.com: "We definitely want more kids sometime soon. Most of next year I'm going to be concentrating on working and stuff, by hopefully by the end of next year."
The former Playboy model, who previously dated Hugh Hefner, loves being a mother and watching her daughter hit new milestones.
She said: "She's crawling, and she's cuter than ever."
Holly also opened up about her other New Year's resolutions.
She said: "To get organised because my life is disorganisation nation right now -- I'm an absolute mess! Literally my house is a mess. Figuratively -- I'm just unorganised in every way."
The model, who wed Pasquale in a lavish Disneyland wedding in September - previously revealed that she was busy teaching her daughter sign language.
She recently said: "Supposedly [babies] can learn to sign before they can speak. It cuts down on a lot of the frustration time, so I've been taking her to sign language class."