Okay, first point: If the ritual is a plot device, why are you using it to create arbitrary distinctions on what can and cannot happen?
Second: She's a mime. As in, does not talk and communicates entirely via visual gestures. Not being heard isn't really an issue since I'd be doing that anyway.
Third: The bond is stated to act as a telepathic link.
Fourth: I am choosing to play this character, and thus you can assume I have picked a character I will enjoy playing.
Finally: Not everything has to directly involve combat. She could, for example, act as a very capable scout or instructor. Try thinking of roles that don't involve brute force (though if having a noncombat character bothers you that much she can, I dunno, shoot lasers by superheating reflective surfaces or something.)