I have been a nurse for over ten years, worked in healthcare for over 15... Psych is not like most specialties, my specialty is psych. I can tell you that my application and the application of people that I know that have also gone into advanced practice like myself are all very unique.
I have one friend who had a perfect 4.0, 1100 gre and was wait-listed post interview
another who had 2.98, 890 and was admitted post interview
another 3.0, 1200, no interview accepted.
We all got into the same program. Its a really good school. I think that I was lucky. I was told that I wrote excellent essays, my background gave me a lot of weight to my application (personal background) and I was willing to be open and honest about why I felt I was perfect for this major and this field... Why I am a rock star as my kids would say.
So, if you think that you would make a great Psych NP, apply, because they look at everything, and anyone who really knows anything knows that undergrad grades that are over ten years old are not reflective of what we are capable now! Neither are GRE's, as I stated to the interviewer, I admit, I was stumped on the Geometry- I have not done Geometry since I was in the 8'th grade (20 years ago...) However, I am a damn good psych nurse, did you read the recommendation I got from so-and-so?
Go for it! the worst the can say is not, and btw, I applied to 13 schools for this fall because I was afraid I would get all no's, and I was surprised, I didnt?