But a flight attendant took away the beverage after the woman allegedly became increasingly aggressive.
Video footage taken by a passenger and shared to TikTok shows a male staffer leaning into a row of seats to try calm the woman down – but her body language suggests otherwise.
He was seen trying to restrain the elderly woman's arms which were violently flailing around.
But after struggling to control her, he stands up – and that's when the raging pensioner in her 70s got up out of her seat and slapped the male employee twice.
Another member of staff is seen helping restrain the woman who falls back into her seat before the clip ends.
A Jet2 spokesperson apologised for the inconvenience caused to fellow passengers.
"We can confirm that flight LS819 from Manchester to Rhodes was diverted to Munich Airport yesterday so that a disruptive passenger could be offloaded," the spokesperson said.
"We would like to apologise to customers for this unforeseen delay and any inconvenience caused."
The footage was shared to TikTok where it attracted more than 25,000 comments.
"Disgusting and unacceptable behaviour anywhere especially in a flight, what the hell is wrong with people?" one person wrote.
Others were also shocked by the elderly woman's act, with one person joking, "Nah as if it was an OAP haha".
"Too much wine. lol," said another, while a third added: "Welcome to the no fly list."
A passenger who was on the flight said the woman had repeatedly asked for free champagne and when the steward told her it wasn't part of the service, she resorted to a gin and tonic.
"She began to get aggressive so the flight attendant removed her drink," the passenger claimed. "She started swearing and having violent outbursts. At one point she got up and tried to open the cabin door mid flight."
The passenger also claimed the woman urinated over three seats.
When the plane landed in Munich, nine police officers allegedly escorted the woman off the flight. The plane was grounded for two hours before eventually making its way to its original destination of Rhodes.
"The health and safety of our colleagues and customers remains our number one priority and, as a family friendly airline, we take a zero-tolerance approach to disruptive behaviour," the Jet2 spokesperson said.
"We will not hesitate to vigorously pursue any costs incurred as a result of this diversion."