I doubt she's trying to herd if she's jumping on them. If it was herding behavior, she'd probably be nipping them and/or blocking them with her body.
You're going to have to teach her how to play with them. This means that you're going to have to be committed to only leaving her out in the yard with them when a parent is there to train the dog, at least for the time being. It isn't something that's going to fix itself without adult help.
How I'd probably start is teaching her to ignore them when they're running around. Sit outside with her on a leash while they play, and reward her for paying attention to you and ignoring them. It's best if you do this after a long walk or play session, where she's nice and tired--if she's under-exercised and bursting with energy, you're going to be fighting an uphill battle.
Basically, that stage just teaches her that kids running around isn't anything to get too excited about. Sure it's fun, but it happens a lot and she gets all kinds of one-on-one attention and yummy treats from Mom or Dad if she ignores them.
Once she's staying calm on the leash while the kids are playing nearby, you can try letting her off leash. Watch her like a hawk, though. If she starts getting over-excited and especially if she jumps on the child, immediately
remove her from the situation and give her a time-out in a quiet area where no one is paying attention to her. A laundry room or bathroom is good for this. Don't talk to her or scold her, just silently take her there and put her up. Leave her there for 5 minutes or so, then let her out again. Repeat until your kids are tired of playing or she gets the idea.
Herding breeds are very intelligent and she will probably get the idea pretty quickly if you're consistent about it. The only other thing is to make sure she's getting plenty of exercise away from the kids. If she's not, she may be getting so excited she can't really control herself. Those are two very high energy breeds.