I am understanding that this is a female and about two years old? It sounds like she is the only bird, yes?
Female's, even those who have never laid an egg before, can begin to lay at any time. Sometimes an egg gets 'bound' inside and the symptoms you describe are not uncommon for this condition.
It's important to have her seen right away by a vet who knows birds and can diagnose this for sure, then take care of it.
If it goes untreated, the prognosis is serious, so please don't delay.
If you discover it's not egg binding, at least you've done the right thing, will have a much better indication of exactly what it is and how to avoid it in the future (probably with a diet modification).
For now, I'd just urge you to have her seen.
Please follow up with me and let me know. I'll also do what I can to help advise in ideal diet choices for her so you'll have many, many more years of her loving companionship
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You remain responsible, forever, for what you have tamed.
