why do you think doris,cyril and george do not realize they are doing a lot of harm to mrs pearson?

Doris, Cyril and George do not realise that they are doing harm to Mrs. Pearson because they are selfish and self-centred. Their own life and commitments are more important to them than Mrs. Pearson and her well being. They think that as a house wife, Mrs. Pearson does not have a "job", but fail to realise that she does more physical work than any of them.