first of all... you have to consider the type of people that are in modeling. and what happens to the kids.
it may seem cute and wonderful on the outside.. but really, do the kids ever get to just be kids? ? do they ever get any time where they can just not have to be looking 'cute'???
there are millions of cute kids out there, and mand many moms who are pushing their kids into modeling for one reason or another. this isnt a decision you just make because everyone tells you your kids are cute. one persons cute is another persons plain. modeling is a tough tough business, cutthroat, mean, rejecting...
i would really really consider not doing this. enjoy your children, let them be kids. if when they are adults modeling is somethign they will enjoy, then great! they can make their good decisions about money and saving then... and still have plenty of time before retirement. chances are for years and years you may be running from here to there and all over to different auditions (or whatever they call them) and you may never make a penny.
think about the stories you hear about childrens modeling ... they are not happy stories. there are too few that are actually successful, happy, normal families...
i highly recommend that no one make their kids model. however, magazines like parents or parenting (i cant remember which one but maybe both) usually do yearly cute kid contests. these seem to be low-key, and simple... and fun. doing something like that might be ok. but i really dont know how much fun a kid in the modeling industry could really have.... and all the pressures to be perfect and cute... all the time?? where does that end? what kind of older children do they turn out to be? what kind of teenager??
you do what you think is best for your children and your family. just being told that your kids are cute isnt really reason to jump into a vicious, evil industry... it could cost you more than its ever worth... even if they would "make it big"... it could cost them their lives.
just let kids be kids... let them choose to model as an adult. theres more money in that anyway. :D