I've read that constant nose picking can wider your nostrils and your nose. is it true? also, can staph in nose cause staph in vagina?

Nose picking has no effect on nose or nostril shape. When anywhere on the body, usually staph is everywhere. If in your nose, you can safely assume it's also on your skin, in the genital and anal area, the vagina, and so on. This isn't necessarily abnormal. Nothing need be done unless you're having staph infections, like skin boils; or if you or a household member has severe immune deficiency.