Visas for the UK - Can disability be an exemption for the fiance visa ?

I'm looking to move to the England from Canada under a Fiance Visa, but my Fiance who is a British Citizen is unable to work for a year or so and it says the sponsor needs to be earning 18600 a year.

This is impossible for her as she needs physiotherapy sessions a few times a week which would get in the way of working, and she needs to apply for Disability Living Allowance which doesn't provide that amount of money.

And even when she is able to work, it wont be full time or in a high powered job.

Would her condition be an acceptance? Could the household income of where we'd be living help to prove that we'd be capable of supporting ourselves within it?

I would look for work ASAP, and we wouldn't be living in our own place together until she's capable of working, so we'd only need to contribute towards rent and bills, not pay full ones.

It says that exemptions are made for people getting disability benefits, but I'm still anxious that she might not fall under that for whatever reason.

Please help, Thank you.