To my knowledge, she has not started laying yet this year. IN fact, I have begun to even wonder if she really is a 'she'. However, last year, I got two eggs on several different days, and these two birds are the only two that could've laid them...Has she just finished laying for the season? I would say she sounds like she is calcium deficient. Laying takes a lot out of them and if you offer an all flock feed it is often too low in calcium. I put my laying geese on 16% layer pellets with calcium while they are laying and afterwards. I also offer free choice oyster shell and a nut mix that is a bird feed mix in small quantities (a lot of sebbie breeders swear by supplementing after the laying season is over with nut mixes that are high in calcium)
I would put her in a dog crate for 24 hours with lots of fresh grass hand fuls, give her a couple calcium pills if you have them and put some layer pellets and lots of fresh water in front of her. I had a goose that collapsed this spring after setting a clutch of eggs and she was just weak from laying and it sucked the life right out of her. Gave her a couple 500 mg calcium tablets, put her in a crate and the next day she was good as new. Worth a try!
I do provide my birds with oyster shell and have noticed that we seem to be going through it faster than usual. Is the oyster shell not enough of a calcium supplement? I feed my birds 16% all purpose poultry crumbles mixed with some corn and milo. They free range nearly every day, usually for about 10-12 hours per day.