It sounds like everyone around her just believed what Roy Meadows said. So she was abandoned.
Women like Sally Clarke and Angela Cannings had the support of their husbands and families and friends, who simply couldn't believe that they had done it, and who also had a healthy disrespect for "expert opinion". It looks like poor Donna didn't have that advantage. And her mother died while she was in prison, so she has no-one.
So, so sad.