If her ears aren't floppy now...they probably won't ever be. And to be registered NOA Nubian...the ears have to come down past the nose by an inch or two.
From reading my ADGA Guidebook(such a confusing thing sometimes!) it doesn't sound like she will be able to be recorded as NOA. It says:
A doe of unknown pedigree may be recorded as a Native on Appearance (NOA) if the application is accompanied by a statement signed by an ADGA member, not a member of the applicant's family, that the doe being recorded conforms to a specific breed type.
You'll have to call ADGA to be sure.
There is this also:
A doe of unknown pedigree may be recorded as a Native on Performance (NOP) Grade Experimental if the doe earns the equivalent of her *M rating on DHIA test. The individual doe lactation record page showing the total milk, butterfat, and production must accompany the application. The doe can be recorded as a NOP and simultaneously be awarded her *M status after the proper forms are filed and fees are paid.