Angel Nicki's rocks are always free. However, Angel's friends have encouraged her to allow people to make donations if they want to. Most of the donations go towards more rock painting supplies... although sometimes Angel uses it for living expenses such as cat food.
There are multiple ways that you can donate to Angel. But nobody has to donate anything. The rocks are meant to spread joy!
if you go to the restaurant at Shorewood, you can also leave cash in the donation  bucket which is with the rocks. Or if you know Jason from Speedy Glass, you could just give it to him because he always looks out for Angel. But otherwise, here are your choices...

Use GoFundMe to make a donation for Angel!