She had been in the laundry area of the house and looked up to see a light coming from the garage which she had locked about 7pm.
"I looked and saw a glow. I don't know what it was but I thought 'fire'. Luckily the firemen came quickly, otherwise the house might have burned."
Ms Spence said she dialled 111 but was too upset to speak to the operator and had to hand the phone to a customer. She moved her car from near the garage and then went inside the house to grab her jewellery and passport.
"It happened so fast."
The garage was stacked with her belongings and those of two staff members who had moved into the business four months ago. Ms Spence had no contents insurance.
The business was not affected and yesterday the staff were preparing for another busy day.
Fire investigator Terry Baylis said the fire had started at the back of the garage, where there was a sofa, but he did not know what had caused it.