Lyndsay Dewey set well-known busker Graham Sawyer’s bedding alight on October 6, and the flames then spread to the Laura Ashley shop in Montague Street.
The 41-year-old, of no fixed address, appeared at Lewes Crown Court yesterday, where she pleaded guilty to two charges of arson.
Rough sleeper Mr Sawyer is well-known in the Worthing community, often playing his guitar outside the Laura Ashley store.
Firefighters and police were alerted to the fire, which spread from his bedding to the store itself.
The fire was swiftly extinguished, but the Laura Ashley store had to close for two days while repairs were carried out.
Fortunately Mr Sawyer’s guitar was undamaged in the incident, and new bedding was donated to him.
Defence barrister Mr Watson said Dewey has a ‘background of drug addiction’.
He added: “She wishes to rid herself of these drugs.”
Judge Christine Laing QC told her that the offences are ‘very serious’.
She continued: “Setting fire to the belongings of a homeless person in a very deliberate way when these belonging were up against a shopfront in a public pavilion seem to be very dangerous.
“The defendant should be under no illusion – this crosses the custody threshold by some margin.
“Custody is the most likely option.”
Sentencing was adjourned to allow for a pre-sentence report to be carried out.
Dewey was remanded in custody until her sentencing, which will take place in January.