Mrs Kelly, from Thurcroft, near Rotherham, and 30 friends saved up for the holiday and left maid of honour Charlene Whittaker to keep the money.
But, three days before the party were due to fly out to Spain, 29-year-old Whittaker told them the flights had been cancelled.
They then discovered that, in fact, the trip had never been booked, and Whittaker, of Rackford Road in North Anston, had kept the money.
She admitted theft and was given 80 hours of community service by magistrates in Rotherham. She was also ordered to pay £1,410 compensation and £75 costs.
Mrs Kelly, a hairdresser, said: “I thought that she was my best friend. I couldn’t believe it when I found out she had done this.”
The hen party was planned for May last year but Whittaker began collecting payments a year earlier.
Days before the trip, she told the other women that the flight was cancelled – but they then found out that it had never been booked.
Mrs Kelly and her friends hastily made their own arrangements to fly to Spain, and she married fiancé James Kelly in September.
After the honeymoon Mrs Kelly and her friends decided to call the police.
She said: “I still don’t know why she did it.
“If I saw her now I would just ask her why.”