SISTER; represents sisterly bonds(of which yours seem lacking according to the emotion of this dream)
CHILD; represents that aspect of yourself. your insecurities and innocence, but also your desire to learn new things and your craving for guidance.
PHONE; indicates you may expect some news in the near future. It also represents communication(which also seems to be lacking in your waking-life)
DRIVING; represents the manner in which you are controlling your life. Complying with the childs wishes to drive would indicate you might rather let someone else take control regardless of the risks involved.
OVER-ALL- there seems to be strong indications of mixd messages, insecurities, miscommunication,feelings of neglect (or not being included) in your sisters "affairs".
Perhaps you could discuss this dream with your sister(to open the door of communication) and let her know your concerns.
Sweet dreams,

Dreamguide