Ann:
It's hard to answer you in a general way. There are so many different kinds of moles and spots, and even those which change with time and show some irregularity are usually nothing. Besides, it's hard to diagnose yourself or your kids. My advice is to bring any new or questionable moles to the attention of your primary physician, who can tell you whether to ignore them, watch them, or take them off. Once you learn a mole is OK, you can generally forget about it.
Best.
Dr. Rockoff