I read often about peafowl going 50-60.. but personally I doubt that... my Blue male is nearing 26 and he definitely looks "old".. would not be surprised if he passes within 5 years.
Hens do lay for many years, up to 15-20 years. As for season-wise, if this hen is currently laying, she will stop soon and not lay again until spring.
BTW peahens are considered to be fully mature at 3 years.. males are fully colored out at 3 years but they get "a little better" every year until 6 years.
So they are long lived and long-breeding birds for sure at the very least.