What happens to the children?

This is our new reality.
There is no right or wrong answer, the world is a huge petri dish of experimentation

I suppose that if both parents live together and are off work, at least one of them can return. I'm worried about public transport, though. I can't see many people wanting to squeeze into the tubes for London any time soon.

Why have they contacted you? Are you a child care provider? If so, I imagine guidance will be given soon.

As others say, this is all new territory, so everyone is feeling their way. If a non-key-worker job can be done from home then I would ask the employer to do a risk assessment before returning to work. One person could return to work, or maybe each could go work on alternative days/weeks.

Schools are being given advice as to how to manage the environment to make it safe for everyone. It could include only half the children going in, for half the time, meaning more space can be given to them. I’m not sure teachers would be any more or less likely to need to self-isolate than any other section of working age society.

My DD, her husband and child have been keeping to the rules of isolation. They were both furloughed.
I would be prepared to accept that none of them have the virus. I know we haven’t.

I would, in our case, suggest that DGS could move in here.
Whether that would be allowed I don’t know. If we could all be tested it would make a decision like that much easier to make.

Have none of them left home since lockdown started? They would need to have been totally quarantined (ie not leaving the house at all) for two weeks for you to be sure that nobody is a carrier.

My guess is that most primary school children will not be returning to school until September at the earliest. The talk is of allowing Year 6 to return first. Schools have been promised that they will be given at least two weeks notice before any return.