One pupil dilated, headaches, aching in neck and more

My sister’s roommate (mid 40s, female) has had one pupil dilated more than the other for over a month. Went to the ER, scans of brain/eye didn’t find anything (except something “very very small” but weren’t concerned—she needs to point back to that maybe). Since then symptoms are getting worse—now a constant bad headaches and neck ache. Tight shoulders. So uncomfortable she can’t sleep well or eat much and is losing weight. She had a standing PT appt the other day and he found that she had very little reflex response on her knees and feet. And now some facial numbness. Note, she had cancer (I think) as a teen and since seems to have a lower immune system (gets sick frequently; my sister was wondering if mold in their apartment could do this). Doctors—one this week that told her it was all in her head (asshole) but others who are believing her. She’d gotten an appt with a neurologist for summer, but a great new doc is trying to rush it. So progress there thankfully. But wondering if people here have ideas.