Oh man, I wish I knew how to answer this question because I'm nervous about our Linnies' first eggs too. In theory it should be the same technique as with any other parrot, in which case it depends on what you want to do. If you want her to not get chronic egg laying, you have to start increasing her sleep hours for starters, and if they're already at 12 hours then maybe even kick it up to 14, as well as checking for any disturbances at night. Obviously this is all just preventative, and she's probably not being excessively stimulated as long as she doesn't have anything like a happy hut in her cage or anyone rubbing her butt regularly.
As for what to do with the actual eggs, I'm honestly not so sure. Some people recommend removal when she abandons the eggs, which she should after realizing they're not going to hatch, birds of any parrot species will lay anywhere from one to a large handful of eggs, but eventually this clutch should stop on its' own and she would size the clutch herself, probably 4 or 5 eggs? Other people recommend using dummy eggs, I don't really understand all the logistics on what to do in the moment of egg laying.
A nesting box is probably not necessary, as far as i'm aware you only get one to encourage nesting for pairs or girls at a certain time of year so you can get them on a healthy breeding cycle, and since she's already eggnant it'd only extend her clutch out even further.
