NRHA Question

I have a little light grey 16 year old mare that has been trained in reining, I want to show her but she is grade. Would she still qualify for a "Compitition License"? I cannot find this info on their website. Any help would be great! I have aged out of 4-H so I cannot show her thru there, not sure where else she can be shown as most open shows in my area do not have the reining class. Thanks ahead of time.