I'm just going to go on a whim and bump your post, as I'm no breeding or eclectus expert. What kind of light cycle is she currently on, and are you feeding her calcium and/or protein rich foods? Where exactly does she lay the egg - on the bottom grate, in a food bowl? Also, does your husband touch her anywhere below the neck?
The only way I can think of completely stopping her is to just ensure that nothing in the cage (aside from the grate) seems like a viable place to lay an egg. You can look into food crock that she can't crawl into or overtop of if she lays in those, but if she lays on the grate the only alternative I can think of is having something similar in nature to the grate but at a permanent slant so that no single spot seems like a safe place to lay - whether or not that's viable I'm not sure, I'm no expert, but I imagine any bird would feel uncomfortable laying an egg on a slant. Just ensure that if you can manage something like that that there's no risk of injury.
You can try dummy eggs timed with when she'll lay to attempt in fooling her not to lay. Another thing to consider is just going to a certified avian vet, asking them if she's healthy and if her reproductive system is functioning normally, and looking to them for any advice they might have. Egg laying can be due to diet, inappropriate touching, appropriate light cycles/environment, or just hormones taking control. A vet might be able to narrow those down a little bit more for you as well.
Hopefully an eclectus owner pops in soon with some good advice!