Hi!

First how sure are you that it is a female that you have? Has she laid eggs?

Age-wise it is good to get similar aged birds. A 1+ year old male will soon try to court her but you can't really tell unless they are put together for a couple of days. So the real problem is how to be sure that you are getting a male? - unless you are prepared to do DNA-sexing - $25-30 for a $50-80 bird. My experience with Peach-Faced Lovebirds - more females than males out there.

Regards!