'She never went into this as a career landlord, it happened as a result of difficult circumstances for her.'
This shouldn't really be allowed, so many people rent their properties out as it won't sell or similar reasons, but it causes such awful insecurity for tenants. It should be law that people deciding to rent their properties have to allow that property to be rented for a minimum of 5 -10 years, and tenants should be made aware of the likelihood of their rental being sold at the end of it.
I rented for decades until we finally had the means to buy last year. I rented from 2 building firms and HA, as they were the least likely to ask us to leave due to needing/wanting to sell.
I also rented from an accidental landlord, and I can't tell you the stress we went through when he decided to sell after a year or so. It is not easy to find rental properties. At the end of the day it's the tenants home, usually their kids have friends there, they are at school and settled, often you can't find a house in the area if it's a village, quite often you've decorated and spent money on the property, despite knowing it's not yours, because it's your 'home'.
Having said all that, of course it's not the landlords fault, and you should sell in your situation OP if it makes financial sense, and I don't blame you for it at all.
Just wish more HA properties were available, and a lot less accidental landlords, who should really think long and hard before they decide to rent, given that they're highly likely to want to sell within a few years, or in some cases a few months. Definitely needs more regulation.
There should also be more regulation and swifter removal when it comes to nightmare, destructive tenents too.