Can family staff share one login?

They can, but you no longer have to — Settings → Team, owner only, creates a manager login yourself in a few seconds. Enter a name and an email and you are shown a one-time password once, which you hand over; they change it after signing in. Up to 5 manager accounts, each removable with one click when somebody moves on. That is worth doing for one reason above all: the change log then names who did what, which a shared login can never tell you.