I was given two 2 year old Warren hens. One laid 16 eggs in the first 16 days that I had her and then had one day off before starting again. She laid all through the winter too. The other was not quite so good. She stopped laying for about 2 months during the winter. I think it depends on the breed.
It will depend on the breed, the individual bird, the conditions it grew up in, and the conditions she will be/is being kept. I bet she'll be fine.
I took in half a dozen "older" hens ranging from 2-3 years and I am happy with their laying habits. I get two or three eggs a day and I am happy with that.
