After being confronted by police at the scene, the reality star was heard saying “I took drugs, I should not be driving, I admit it all”, the court heard.
A drugs wipe gave a positive reading for cocaine, prosecutor Debbie Jones said.
An image shared by police from the scene on Tuesday showed a car flipped on its side.
Officers responded to the crash at around 6.20am, where Katie was arrested on suspicion of driving while above the legal limit for alcohol and drugs, and was taken to hospital.
Defence solicitor Joe Harrington said: “She has had a lot of personal problems recently.
“Currently she is in the process of bankruptcy proceedings so her house may be repossessed.
“So quite a lot going on in this lady’s life, a really difficult period,” he added.
Mr Harrington argued that the driving was a “one-off” incident.
He added: “As I understand it she had been drinking, she was lonely and she decided to go and see a friend who lived a relatively short distance away and that is when the incident happened.”
He asked magistrates to defer the sentencing for several weeks.
Appearing on ITV’s Good Morning Britain on Monday, Katie claimed she is banned from driving until the end of the year.
Discussing her disabled son Harvey, 19, she said: “Harvey’s in Cheltenham now.
“He keeps ringing me saying, ‘Mummy I miss you, I need kisses and cuddles’, so it is quite hard because obviously I don’t get my licence back until December, so I can’t just whizz in the car down there and it’s not close.”