Correct. It is rude. You're entitled to be pissed off. I note that she did not proactively contact you (good behaviour) well in advance (good behaviour) but instead react (bad behaviour) to your innocuous message a mere few hours before the meeting. The reactivity implies that if you hadn't sent her that message, she might not have even contacted you at all! The beatch!

On other hand, her message is profusely apologetic. Beat that in mind.

Shit like this has happened to many of us.

Your options include:
1. Ignore her
2. Get out there and meet more women
3. Work with her regardless, another chance, and see where it goes
4. Scold her behaviour (for your own satisfaction; without caring whether she responds positively or not)
5. Sympathise with her "something has come up at home", must be genuine emergency

The above are not mutually exclusive! An example combination is:

2. Get out there and meet more women, whilst...
3. Work with her regardless, another chance, and see where it goes

Regarding #3, you can easily keep her in your orbit just with occasional short text messages, then meet up with her on your terms and conveniece (e.g. nearer to where you live rather than her). If you see her as a fuck buddy you should be able to tolerate her daft behaviour, but seeing her as girlfriend material, then probably not... unless you discover that -- hey! -- there really was some serious family/home thing, with her sister ill and about to pass out, and it genuinely did get hyper-prioritized ahead of some guy she's briefly met...