1. lawyers.
2. Valuations change, The virus has turned businesses into sand so it doesn't really matter what was valued 9 months ago. No-one would pay for a B+B business now at the pre-covid rates, there is zero timescale on when a business like that will improve. Could be a year, two or even three. Its a big risk.
3. Your mothers getting old, 100k is a nice sum to have sitting in the bank account to do WHATEVER she wants with. What's the alternative? a long legal battle that would be eaten up with fees anyway, stress, and no moving on from her now ex partner? Who cares if he keeps the hotel? Hes taking the risk and as long as the documents show that your mother is fully out of it then she doesn't have a care in the world
I know which one id choose.