Female Budgie biting more

[Smores]

I have a young male and female budgie (same cage). We have had them for about 6 months. We had done a lot of hand training with and without miller spray with them both and had progressed pretty far but in the last month she has started biting our fingers. I assumed this was a warning of some kind, but am becoming more concerned as it is much more frequent. We suspect she has always been a little more territorial. But never gone as far as her vice grip biting. Any help?

 

[Sparkles99]

Though all of mine have been male, I understand this is normal for female budgies - they may just be sassier. @AussieBird