Hi fellow Australian @Tam48 !
To be honest I think this girl walked all over you. I agree with @Pete69 a FREE NIGHT? A choc bar or a bottle of wine MAYBE for the inconvenience, that would be it.
I've had a quick look at your listing and your see very clearly check out is "firmly 11 am." Even if this guest is new to airbnb, that's pretty hard to misunderstand. Airbnb send guests several automated messages confirnimg details such as this, so I find it hard to believe there was genuine confusion on your guests part. She was just rude.
I find saying anything negative in a public review difficult, but I would be inclined to mention this in this instance - I would want to know she had behaved like that if she were coming to my place. maybe something like XXX was a polite, friendly guest who left her room very clean. However she arrived xx hours early for check in adn left 3 hours late for checkout without any prior discussion or communication, which did cause me some difficulties. xxx would make an better future guest when she is more attentive to check in and check out proceedures. I would mark her down on observance of house rules. You sound like a very kind and diplomatic person so you can probably word this better than me.
Moving forward, to try to prevent his sort of thing happening again, I have found the following strategies really helpful.
* leave a folder with the house rules, and check out proceedure - including check out time - in the guest room. Ipersonally use a lovely big font with plenty of white space between the lines so it's easy on teh eyes to flip through and read/
*use the option to put a security deposit on your listing - make it quite a lot as you have new carpets etc. ( mine is $500).
*Specifically refer to your security deposit in your listing desctiption and note that so long as house rules are followed and no damage occurs, there should be absolutely no problem with guests retaining their security deposit.
It just makes guests think twice, maybe 3 times before doing the wrong thing. You'll find that "casual" guest such as this one magically notice these sorts of details and either go elsewhere or beahve. And that way you don't have to face so assertive face to face, which is something I think you might struggle with.
I've never had a single guest question or complain about the security depsoit - but several have assured me they plan to take excellent care of my home. Its not foolproof of course but I think it really helps.
I was in your position just a few months ago and I vividly remember how tough I found it trying to be gracious and generous and kind ( and get good reviews) without being pushed around - you'll find it won't take you very long to find your mojo. Good luck.
ps if you decide you DO want to make a comment on the public review, you might want to consider posting what you plan to say on these boards first to get some advice from other hosts - people are usually most helpful re this and you can pick and choose different phrases and approaches to suit you individual opinion and style.
Cheers