Amanda Donaldson, 35, was suspended and later dismissed in 2017 over alleged unauthorised spending and the taking of Harry Potter merchandise to a total value of almost £24,000.
The author is seeking damages in a civil case brought under her married name Joanne Murray, and alleges Ms Donaldson made transactions including £3,629 in retailer Molton Brown, £2,139 in card shop Paper Tiger and more than £1,800 in Starbucks and Costa coffee shops on a company credit card without authorisation.
Giving evidence at Airdrie Sheriff Court, Ms Donaldson said the author “could be really generous” and bought her a replacement pushchair when her child’s original was damaged.
But she claimed she was never given specific instructions for the use of the company credit card.
Ms Donaldson said Ms Rowling was often “busy writing and you had to respect that”.
She added: “Approachable isn’t something I would say.
“People in the office would sometimes ask if she was in a good mood, in a terrified way.”
The PA said her boss had asked her to buy cards and gift wrapping that she got in Paper Tiger and claimed thousands of pounds spent on cakes and coffees were for business meetings and staff birthdays.
Ms Donaldson said the purchases in Molton Brown were for the office while spending in Jo Malone was at the request of Ms Rowling.
The defendant said she was told not to disturb the author when she was busy so had to make her own spending decisions.
“It was my understanding I would make the decision and would tell her after what I had done. I was never told otherwise,” Ms Donaldson said.
Questioned on how she responded to the fraud allegations, the 35-year-old said: “I really respected my role and would never have dreamed of doing anything like that.
“I’m quite offended and hurt (by the accusation).”
Ms Donaldson was later asked by her lawyer Allana Turley: “As far as you were aware what you were doing with the card you were allowed to do?”
The PA said: “That’s correct.”
The civil case before Sheriff Derek O’Carroll continues.