Thats great boheninan so are you going to go ahead and be an adopted 'Gran'?It's just finding people that are local to you all really, isn't it? I am already a Gran, so don't have time to be an adopted one though.
I will say, that when growing up my children did not have any Grandparents at all [all died] and I always felt they were missing out, but when I talked to them about this, it transpired that they were not at all bothered.They had myself and their Father at home and were surprised that I was worried by this.So I stopped worrying. However I can see that if the child/children are young enough to accept an older stranger in their life, that can be a real force for good.Children will be choosy though and if there is something they don't like or scares them about an older person that they are not used to they will say so! Good luck everyone.
To think that London, or anywhere else for that matter, does not belong to any one demographic