I remember reading a sci-fi adventure-drama graphic novel in elementary school that had a simplistic and cartoony art style. I believe that the main protagonist was a girl and she had a giant mouse companion who wore a device that translated his mouse noises into words on paper.
I also remember a floating spherical droid that was similar to V.I.N.CENT from The Black Hole (1979) and an antagonistic robot that appeared as a mass of thread-thin tendrils coming out of a scubadiving helmet.
There was also a broken robot who was revealed to be a starkilling superweapon.
Despite my best efforts, I cannot find anything close to this novel online.