Rent reductions

Rent Arrears

My tenant contacted me April 2020 to say she was in employment difficulties. I reduced the rent in writing by %C2£210 for 3 months with no debt to tenant. She then paid in full for a few months but was in trouble again by November. I halved the December rent and reduced the next 3 months by %C2£210, again as a straight reduction (and detailed in writing). I have the sense from the tenant although she hasn't asked directly yet that she will be unable to resume the full rent on time. I am not sure what to do next. I.e. it's going to be difficult for me if this becomes permanent, I don't wish to be taken advantage of, but I don't wish to be unkind either. So far as I can tell the usual rent is already good value for the area. Is it reasonable to suggest if I reduce the rent for a further period that the tenant then owes the unpaid rent at a later date? Or should I carry on reducing a bit longer until the country is further past lock down? Or are there other suggestions?