Judith Smelt, formerly the office administrator, said Lorraine Field "had a good rapport with [the residents] and they all seemed to be very fond of her".
Mrs Field, 42, of Stoke Poges, Buckinghamshire, has denied four counts of ill-treating residents at two residential homes formerly run by a company called Longcare in the town.
Another former member of staff, Desmond Tully, 33, of Exeter, Devon, also denies four charges of ill-treating residents. And former company director Angela Rowe, 39, of Windsor, Berkshire, denies two counts of ill-treating and two of wilfully neglecting residents in her care.
Kingston Crown Court also heard testimony from current colleagues of Mr Tully that he has "done a good job" at a home he now runs in Devon.
But in his closing speech for the prosecution, Jonathan Caplan QC, said the jury must assess the "compelling" evidence against all three defendants.
"This case is not about best practice, how best to run residential care homes for the mentally disabled. It's a case about falling below what is acceptable in running such homes and falling into the realms of the criminal law," he said.
He added that caring for the mentally disabled could be "demanding, frustrating, possibly risky, but that does not give anybody who has such a person in their care a license to ill-treat that person or to neglect their welfare".Reuse content