I would try this...

First, only allow LuLu near children when supervised but do try to arrange for or find some safe, controlled situations where you could work with her near children.

Using a hand signal, voice correction ("No" or "Hey!"), clapping hands or any other simple communication tool, demand that LuLu allow lots of space to any children that are around. She cannot get within several feet of the children. If she comes past your "invisible boundary", and especially if she growls, use the clap or "No" or whatever correction you're using to get her attention until she stops (and hopefully looks at you). Stand confidently between her and the children, if need be, and look her directly in the eye and point to her when doing this to show you're serious. Just like a parent giving their misbehaving kid that "look". She needs to respect children and their space. This puts the children (and you) in the dominant role.

Do that for at least a couple of weeks till she is giving the children space or, better yet, ignoring them completely. Slowly allow her to come closer to the children as time goes on (calling her to you if necessary), but only if she approaches with her ears back, head slightly down (show of submission) and a tail that is either slightly down or at least level with the floor. (A stiff, raised tail is dominance, a tail between the legs is fear which can lead to aggression).

If you consistently follow & enforce these rules every time children are around, soon she'll learn that children are to be respected. Once she reaches that point, the children could start calling her to them to receive petting, but they should never approach LuLu themselves as that puts LuLu in the dominant role again. The children should be taught to always call LuLu to them, never to go running up to her.

If you're not already doing it, I would also make sure she is on a strict "earn-your-keep" type program where she has to earn every good thing she gets from you. Make her sit or down to get a pet, or food, or a treat, or water. Only let her on the bed or sofa with your permission, feed her only after you eat and so on. She'll figure out pretty quickly that the humans in the house are the alphas... And probably be a happier, more confident girl for it!

Good luck!