 Following her father 's death , Donna adopted her half @-@ niece Mia . Discussing the development in the context of her 2010 Casualty appearance , Jacobs explained that it made her ED shift particularly stressful as " she now has little Mia to look after – if anything happens to Donna , Mia is completely on her own . " She expanded that , " The stakes have really moved on for Donna over the last couple of years . She 's had to accept some responsibility and it 's not now just about which man she 's going to sleep with next " . 
