Power lines also came down, scorching the roof and bonnet of her husband's car, she said.
Realising there could be a tsunami, they ran around to the neighbour's house after trying to flag people down, and got a lift to higher ground.
Mrs Knowles said the experience was "extremely scary, it freaked us out".
As she and her friend had their cars with them, they were stuck until the roads reopened.
Mrs Knowles said it was hoped the inland road would open Saturday at the earliest and she expected a convoy of cars heading out of the stricken town.
She said helicopters had been flying in and out constantly over the last couple of days, trying to get the elderly and sick out first.
She said locals, the Civil Defence and Red Cross had been amazing.
They had slept at the main Civil Defence headquarters where people were provided with blankets, candles and radios, as well as being kept informed, she said.
"For the first 24 hours you felt like you were in the dark."
She said it felt like they were getting more information now, and there were briefings at 1pm each day.
They were now staying at the Kaikoura Top 10 Holiday Park.
Mrs Knowles said aftershocks had been constant and there had probably been at least one every 15 minutes.
The HMNZS Canterbury left Auckland on Monday night, bound for Kaikoura to evacuate stranded tourists.
However, the navy vessel was not expected to begin evacuating people until first light Wednesday morning.
She is not the only local stranded in the town. Rotorua couple Jamie Brosnahan and Jonathon O'Neill are also there, with their rental car and mountain bikes.
