Also, if she does lay try to reduce any conditions that might be signaling to her that it's egg-laying time. Longer daylight hours, an abundance of richer foods, access to dark and cozy (nesty) type areas, and being touched on her back, under her wings, around her groin area (of course), or stroked the length of her tail would all be triggers for hormonal/nesting behaviors.
So you'd want to reduce her daylight hours and make sure she gets a solid 10-12 hours of sleep, cut down on her more sugary foods, keep her away from areas she might see as nesting hollows, and cease any type of touching she may be misreading as sexual advances.
Also make sure to up her calcium intake whenever she's laying and, as SailBoat already recommended, get in touch with a certified avian vet. Though she's young yet, so you have some time before this has the potential of becoming an issue.