b) Attached/related/close to mean 3 different things. If you're attached to someone it means that you have an important relationship with them. If you're related, then you are part of the same family. If you're close to them, you're very good friends and probably know a lot about each other.
c) A governess and a babysitter are entirely different. A governess is a rather old-fashioned term but it meant a woman who was employed to teach a child in the home instead of, or in addition to, at school. A babysitter is simply someone who comes to your house and looks after your child while you're out for a short period of time. Someone who lives in your house and looks after your children is either a nanny or an au pair.