From what she says, she has undoubtedly come up against some people who have wanted to make life pretty uncomfortable for her, but as this is now 3 jobs in a row, I can't help thinking maybe it has something to do with her?
Examples are that "even 5 mins late is a big drama" well she's only been in the job a few months, I've only been late for work twice in 20 years, so perhaps they have a point.
"can't take a minute longer than an hour for lunch" well, bearing in mind your colleagues have to cover for you...
And heaven forbid, if anyone suggests she should stay after 5pm!
She gets herself into a real state over it, to the extent that she left the last job practically on doctor's orders, but she says this one is worse.
How can I explain gently, that a lot of what she complains about seems normal to me, that her colleagues are entitled to be a bit put out if she takes the p**s and that her boss (company owner) is entitled to expect her to earn her salary?