Retirement seems to have left Ashleigh Barty busier than ever. The former World No.1 received one of her country's top honors on Sunday -- then had some fun on a water slide in a nationally-televised event to support charity the very next day.

On Sunday, Barty was announced as an Officer of the Order of Australia (AO) in the Queen's Birthday Honors. One of the highest accolades an Australian can receive, the AO is awarded for distinguished service of a high degree to Australia or to humanity at large.

Three-time Grand Slam champion Barty, 26, received the honor for distinguished service to tennis at the elite level and to youth development programs.

"Recipients share some common traits – including selflessness, excellence and a commitment to service," said Governor-General David Hurley. "They're from different backgrounds, their stories are each unique, and each has served in different ways. ... This diversity is a strength and each has impacted their community and made it better."

Then on Monday, Barty took part in the eighth edition of The Big Freeze, where celebrities tumble down a water slide in costume, plunging into an ice-cold pool to raise awareness and funds to fight Motor Neurone Disease.

Barty was dressed as Rafiki from "The Lion King," and she hoisted a stuffed Simba into the air as she landed in the chilly water ahead of the Australian rules football game between Collingwood and Melbourne.

Barty and Simba before their drop.

Darrian Traynor/Getty Images

"I hoped I performed a little bit better on the tennis court, but this is just the most beautiful day for the right reasons," Barty said after finishing her descent.

Barty and her fellow celebrities surpassed their goal of two million dollars in donations for the FightMND charity.

The Aussie legend has been gathering plaudits and experiences since announcing her retirement in March while still ranked World No.1. Barty ended her career on top, winning her third Grand Slam title on home soil at the Australian Open in her final event.