Tenants in common is a concept that doesn't exist across the whole UK,
only in England and Wales. The OP doesn't say that that they are
domiciled in one of those countries.
I'm not convinced that the answer is correct. For a start, if the there
is a tenants in common arrangement, the will will need to indicate who
gets your share of the house, and their legacy will be reduced by the
amount of your debt. I'm not sure whether they would be forced to sell
their share (the part obtained from you if they are the other tenant),
or whether it would always possible to make a charge on the property.
My feeling is that, if you are at risk of this happening, this is one of
those times where internet forum/newsgroup advice is not enough. At the
very least, talk to a debt counselling charity, maybe start with the CAB.
(If I read
correctly, the ownership arrangement that would be desirable would be
"joint tenancy". Attempts to change the tenancy when the likelihood of
default was known would probably be treated as void, unless done by
buying out the share at full market value.)
Can you confirm you live in England and Wales as another poster has
intimated the situation is a little different in Scotland?
Tenants in common means the house is all hers as well as all yours. The
house will be just hers after your death. The debt will be offset to
your estate which you indicate is nothing.
As long as she hasn't signed any guarantees or allowed the house to be
used as surety all should be good.
What is interesting is that should she die before you, you're still
responsible for her debts.