 Jacobs was cast as Donna immediately after leaving drama school , and considers herself " completely blessed " for having won the role . She was cast alongside fellow series six newcomer Kelly Adams , as midwife Mickie Hendrie . A BBC documentary entitled Making It at Holby chronicled their casting process , which entailed seven weeks of auditions , including group workshops to allow the series producers to gauge candidates ' personalities . Adams originally auditioned as Donna , however the casting directors felt that she would be better suited to Mickie , the quieter character , and " mild mannered " counterpart to Donna 's " sassy staff nurse " . She and Jacobs were paired together during a three @-@ hour workshop , and the producers detected an " instant spark " between them , leading to their dual casting . Following her successful audition , Jacobs was mentored by actress Jan Pearson , who played ward sister Kath Fox . 
