stop young mum being kicked out

my sister turned 21 just days before our mum passed away, now on top of having to come to terms with our loss we have been told my sister and her 2 young children will have to leave their home as it was a council property in my mums name. This just doesn't make sense, she is entitled to a 2 bed council property, that's what shes living in, Corby council want to move her into another 2 bed property and give her house to someone else for absolutely no reason we can find. Not only will this cause stress to my sister and her family it will also involve alot of extra work for the council. How can this be a justifiable way of spending tax payers money?