Some info here re the Work Bonus.

https://www.dss.gov.au/seniors/programmes-services/work-bonus

Currently

The Work Bonus provides an incentive for pensioners over Age Pension age to participate in the workforce by allowing them to keep more of their pension when they have earnings from working. The Work Bonus increases the amount an eligible employed pensioner can earn from employment before it affects their pension rate. Currently, the first $250 of fortnightly employment income is not assessed and is not counted under the pension income test.

1 July 2019 Changes to the Work Bonus

From 1 July 2019, both employed and self-employed social security pensioners over pension age will be eligible for the Work Bonus, and able to earn up to $300 per fortnight from work before this income is assessed under the pension income test. Additionally, the Work Bonus maximum accrual amount will increase to $7,800.

Tilt ... hoping this helps. Full details on link above.

You have always been able to be self employed and receive a Pension, depending upon your income from it of course.

$300 a fn. That's $150 pw or around $20/day. This can be earned in just one hour! Or, u may want to work one day a week x $150 (couples) ...

Is that realistic? 

I am self-employed (very much part-time) and have been getting the age pension for some years.

The only change here is that the work bonus will be available to self-employed pensioners, whereas it was previously only available to those worked for an employer other than themselves. To date I have had to submit a profit/loss report on a regular basis and my pension has been adjusted accordingly. This policy change will lessen the impact on my pension amount, and grant me a few pennies more.