So DM (working, healthy, in her 60s) has always been terrible with money and has a lot of debt hanging over her. The family home which has been on a 100% LTV interest only mortgage is coming to the end of its term next year and due to her age she will not be able to get a re-mortgage without getting involved in some dreadful equity release scheme or some such.
There is no question of downsizing or selling the property as she will not hear of moving house. The plan I have come up with is for me and DH to buy the family home for the price of the mortgage (i.e. being gifted £175k of equity which has been gained through price rise alone) and to then pay a repayment mortgage allowing DM to live there rent-free. This would mean that the family home is kept, the equity is not lost (particularly to pay off her other debts) and that she would free up significant monthly income by not paying the mortgage to pay off these other debts.
The issue is that I have a sister and I am concerned that she may see this as me taking away any chance of an inheritance? For background, although we have similar salaries she would not have the financial capacity to do this as she has just bought her own house (after living in the family home for 15 years not paying rent, bills or food). When she was looking for properties, I encouraged her several times to buy the family home instead but each time she refused (it is not in the best state of repair however perfectly liveable). As far as she knows, the family house is written off and is to be used to pay off debts etc. Also by DH and I taking this on, it will mean we are unable to upgrade our own home (living in a 1 bed flat) which means that we are taking on a big hit to our personal life e.g. less space to start a family. It has taken considerable stress and research in order to plan this and she would never have put forward this herself.
I feel that if we pay into this for say the next 20 years the proceeds from the resultant sale should be ours? However if by some terrible misfortune DM passed away in the next 5 years I accept that it would be best to share with DSis – perhaps two thirds to one thirds? AIBU?