Q: I recently started working with a student with a right side unilateral lisp caused by jaw and tongue instability. He also has a midline bulge. Right now we are working on maintaining a stable jaw. Do I focus on tongue position as well?

It sounds like he is shifting both his jaw and his tongue to one side. If so, stabilize the jaw first and use a straw to analyze what is going on with the airstream with the jaw in place. Sometimes the jaw re-adjustment alone takes care of it, sometimes you have to work on the tongue too.  In fact, if his tongue is bulging upward in the middle section, then I am almost certain you will have to do the tongue too. Use the straw to teach him midline airstream off of T.