You have a gorgeous female there!
Her cere is the color of an adult female out of breeding condition.
I can tell you she is an adult as indicated by the white iris rings on her eyes. They are done turning color completely, so my guess is at least a year.
Once a bird has lost it's baby features in it's feather coloring and eye color, there isn't a way to tell if she is 1 year vs. 5 years. For example, you can look at it like this.. with dogs, once they are full grown but not yet showing any signs of getting old, you really can't say a definite age, you can just say young adult or middle aged. With dogs, a further clue is looking at the wear of the teeth, so birds have even less to go on.
I'm sure our mutations experts will come along and say what the absolutely gorgeous
mutation you have here is... Lacewing? I really don't know, but I can say I am a bit envious