The summer between my high school graduation and my first year of college, I worked for the a computer company located in a 12-story building. So did "Chris" (aka Richard) while s/he was undergoing the initial stages (i.e. hormones and cross-dressing) of "sex-reassignment". S/he had to use the "ladies" room on the first floor of the building only, and every woman in the building was so informed.
IMO, once "Jennifer" has "his" surgery, "she" should be able to use the ladies room. Until then, "he" should hold it.