@eeeefarm:
Cheap & dirty solution: tell the kids to stay away from the dog. Let her approach them, if she is so inclined. ..
Except that if you blink, and a child gets near and gets bit, you and your dog pay the price. Absolutely they need to keep this dog away from children, muzzled or on a leash if they have to be near them, until they get this solved. But aggression to children is a danger forever in our society. They have a baby who will soon BE that age, who will have friends over, who will simply make your approach undoable.
IF the issue is a child has been mean or frightened her, the fix is a bit easier but takes time. Solicit friends, neighbors and countrymen to lend you their children. Take your dog outside on a leash or inside a fence, or leashed inside. Have children drop by, toss a treat– that's it, toss a treat. Go on. No other contact. You do this for a couple of weeks even and you will see a big change as you train the dog's automatic response to children to be one of "TREATS! GOOD CHILD!" Then and only then, do you work on letting the dog approach a sitting child who tosses a treat, still no petting. After the dog safely gets treats that way, then consider allow the dog to be pet. These need to be children you trust to be trees and not respond other than treats, not to squeal, etc.
After a while you can take the dog out to parks near kids, keep with you but give treats and praise for calm behaviors or ignoring running excited kids.
IOW you have to totally retrain the response to kids. Talk with your trainer about this method. I am willing to bet they will tell you it is a great support for anything they are doing.