Leeds Crown Court heard mother-of-one Louise Buttery walked in to the elderly man's ground floor flat and demanded money.
Prosecutor. Jessica Mae Randell said the pensioner told Buttery to get out of his flat during the incident just before 11.30pm on November 4.
Miss Randell said 28-year-old Buttery, who has a two-year-old child, punched the man in the stomach and pushed him over.
Miss Randell said Buttery told the man: "I will do what I f***** want you little old b******, I want some money."
The court heard the pensioner had been to a bank that day and offered to give Buttery £10 if she left him alone.
But Buttery grabbed both the man's arms and overpowered him before taking the £90 cash he had.
Miss Randell said Buttery, of Western Lane, Otley, tested positive for cocaine after she was arrested two days later.
Buttery committed the robbery after admitting to a handbag theft on October 26.
A 67 year-old woman and her husband, 72, were walking home from Otley town centre at around 2pm when Buttery snatched the woman's handbag and ran off.
The bag contained £30 cash, £30 worth of lottery tickets, jewellery worth £5 and a £30 mobile phone.
The phone was recovered when Buttery was arrested on October 27 before being interviewed and released on police bail or under investigation.
Miss Randell said Buttery had admitted the handbag theft when she was arrested and said she had done it to pay for drugs.
Miss Randell said the theft victim told police: "The incident really upset me and I lost sleep. I blame myself thinking it was my fault."
Buttery admitted theft and robbery.
She has 27 previous convictions for 44 offences, including burglary, fraud, theft, battery and assault.
Shila Whitehead, mitigating, said Buttery had relapsed and started using drugs again at the time of the offences, adding: "She is remorseful for her actions."
Miss Whitehead said Buttery has a young child who will be aged three in February.
Miss Whitehead said: "She does not want to lose the precious time that she would have with her child."
Jailing Buttery for three-years-and-two-months, Judge Robin Mairs told her: "He was vulnerable and that is why you targeted him."