How patient should you be about people who are late?

So I planned on hanging put with this girl today. We were going to go on my boat and she was going to bring her two kids. I told her we could go like 9:30 or 10 and she agreed. Well it's 11 and haven't heard from her to see whether or not she was going to meet me at my house or the boat ramp. So then she called while I was on the phone with someone else, so I called back and got no answer. I guess the phone hung up on her because my phone never notifies me when someone else is calling unless im looking at the screen. I sort of had already sent her an irritated text because it was my birthday and I felt like she stood me up. She was probably just sleeping, but I'm just tired of putting up with people that ghost me and are just totally disrespectful of my time.

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1 y
So 5hrs later she messages me saying her kid was sick.
Updates
1 y
Still unacceptable in my opinion
How patient should you be about people who are late?
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