If its relevant to your educational experience and can add some value towards dentistry then I'd put it down. Otherwise it makes no sense to add it. Do you expect brownie points for being a mom? Are you using it as an excuse to make up for poor grades? Will it be sympathetic to a female adcom or will she resent you for putting it down? Again no one us know the correct answer here, but unless there's a direct link between motherhood and dentistry or motherhood and the struggle/pursuit of dentistry. I'd leave it out.