Hello.
I also get my pm from Ainterol. It works as it's the only vendor I've bought my pm from.
As for packing, I think it's fairly discrete. It comes in a plain package. However, on the shipping label, it does say Ainterol on the return address. If your girlfriend is curious, she could look up Ainterol online and connect the dots. If you're serious about NBE and if this is a long-term relationship for you, I think it would be best to tell her to get it out of the way.