If you are not planning on breeding or even if you are- as long as you don't have a problem with that registry, go for it! All registries have standards that are to be followed in regards to breed appearance. Some are pickier than others, but I don't think that makes any registry "undesirable" unless you are a breeder and you need to stick with a certain registry of your choice.
If you feel comfortable purchasing a puppy from that breeder, don't let her registry choice stop you.
Good luck! If you get a puppy, we want to see pictures right away!