Setting up a 3DS for someone else?

Drez

I want to set up my old 3DS for my sister. She has no Nintendo presence at all - i think she has a Mii set up on my father's Wii U but that's about it. She has no NNID or Nintendo account of her own.

What I would like to do is format my old 3DS (I believe this is already done when I did my system transfer) and set her up. I would like to purchase a few 3DS games for her off the eShop as well. I don't know if it matters too much but I was going back and forth between purchasing points on the 3DS itself using my CC or buying her points. I don't know if the latter is less of a hassle because I think you have to have a credit card attached to your account anyway. True or False?

Is this even possible, hassle-free, or do I need to . And if I set up an NNID for her and she wants to change the ID later, can she, or is it forever?

Can anyone help guide me here? I'd rather not call her for information if I can avoid it - it's a gift/surprise.

Pailryder

NNID's are relatively permanent barring extreme effort.
you could get her eshop cards which you can use instead of having a credit card.
to avoid the ultimate hassle, make sure you are fully updated and get a large sd card