The original poster mentioned the 'old lady next door' who went to her daughters. Probably that is her bubble family and she is definitely permitted to visit them and they her.
Mental health is as important as physical health.
I went to my bubble family on Christmas Eve and Christmas day, They are just about five or so minutes away from me and also include three teenage children (one a uni student) and a 10-year old. My daughter teaches at a local secondary school. They were all supposed to come to me for Boxing Day (as usual), but we felt that, although within the rules, it would not be fair on other people in my block of flats, so I went to them again
My student g.son had been tested before leaving his Uni halls, The other children and my daughter had been out of their schools for nearly ten days by christmas. My son in law is extremely vulnerable.
So, if the poster lived in my block of flats they would have seen me going out each morning and returning each evening for those three days .