If she is getting ready to retire then it seems quite a reasonable decision not to take on anymore clients who may require,a much longer term relationship.
To take on clients who are going to depend heavily on you for an indefinite time would be irresponsible if you know you can't be there for them.

I doubt it personal like you think, more likely she has come to understand and respect much more what it is to care for someone in your situation.
All the best.