Bossy neighbour needs to be avoided, or if she makes pointed remarks about you helping more next time tell her that is your decision to make and you’ve made it based upon your own age and limitations then change the subject.
The couple in question sound as if they very much want to be left alone anyway, their choice no matter what the situation is, nice to just knock every so often on your way to the shops to see if they need anything, and check how they are, but otherwise let the daughter tackle this one, sounds like she is having problems but she just needs to keep on chipping away.
Has anyone seen Mint on BBC 1?


