Mom can't get the Covid-19 vaccine due to her history of transverse myelitis. Will she be able to return to her senior center when it opens?

Ask her senior center.

Have you spoken to the facility? I would be asking them.

The vaccine is approved under an emergency use authorization by the FDA and that makes any employer or place unable to require it of anyone. The answer should be yes, but I’m also willing to bet on places making their own rules and being hard to fight