The 37-year-old announced her retirement from professional football in June having spent last season with the Magpies and now takes on her first coaching role with her childhood club.
Furness completed her UEFA B License course during her playing career, and she is now working towards her A License.
This season will be the first as a Professional Game Academy (PGA) for the Under-16s, as well as Courtney Vacher's Under-21s.
Furness said: "I'm delighted to be starting my coaching career at my childhood club. I loved playing here and now is my chance to give back to the younger players and inspire them.
"To be involved at a club like this gives me a great opportunity to continue to learn and develop as a coach."