"She has thrown herself back into a full-time job to assist others in need. There's such a demand for qualified medics during these unprecedented times.
"Kate's enjoying doing her little bit to help but we hardly ever see her and Gerry now. They are both so busy."
German prosecutors say they assume Maddie is dead after she disappeared from a holiday apartment in Praia da Luz on May 3, 2007.
Kate and Gerry McCann have said they will "never stop hoping their daughter will be found alive" after 14 years, with no body found and no charges brought.
The McCanns had left Madeleine, then 3, asleep with twin siblings Sean and Amelie to go and eat tapas with their holiday friends. Photo / Getty Images
Her move back to work comes as German police say they are close to having enough evidence to charge paedophile Christian Brueckner with Maddie's disappearance and murder.
German and UK authorities are working together to gather vital evidence.
Recently, police uncovered a secret compound linked to Brueckner.
Located in the southern Algarve region of Portugal – the same area where 3-year-old Maddie vanished from a holiday apartment back in 2007 – the property belongs to Brueckner's ex-girlfriend Nicole Fehlinger.
News of the compound emerged after Fehlinger's father Dieter was recently interviewed for a second time by German authorities, who are reportedly taking the revelation "very seriously".
The McCanns had left Madeleine, then 3, asleep with twin siblings Sean and Amelie to go and eat tapas with their holiday friends. Photo / Getty Images
Dieter claims that his daughter and her former lover Brueckner, 44, were the only people who had access to the compound.
Brueckner maintains he had nothing to do with Maddie's disappearance but refuses to co-operate with police.
Police have recently been given another $689,000 cash boost in a bid to nail Brueckner.
The new cash boost comes as the McCanns have raised more than $1.4m if the money ever dries up.
