It depends if you are going to use an device such as hearing aids or cochlear implants. If that is the case, having your family learning how to sign may be a bit unnecessary. (It is a good idea, it just may be a bit of a learning curve for them.) However if that is not the case, it might be an excellent idea.
Also you can learn how to lip read which is not hard with practice. Knowing how to lip read ensures that a window of communication is always open, regardless of the person you are interacting with. It can also boost the success of HA or CIs because you do not have to rely on them 100%.