I've found that it is harder to potty train the little ones. I had one that was only 3lbs. and I never did get her potty trained. I had to sell her due to her size and me having small kids. It wasn't safe for her. (She was suppose to be a 6-7lb one. Her parents were 7 and 5 lbs.) She was about 20 mos. old when I sold her. I still see her and she still isn't 100 percent potty trained. She is 3 now.