Do you have any ABs to hand?
I would take her into your vets as an emergency tomorrow morning.
Vaginal bleeding can be caused my many things, but unless pus is also coming out with the blood (open pyometeria) it can only be diagnosed in hindsight. Possible other causes are closed pyometeria, other infections, uterine/ ovarian tumours, uterine/ovarian polyps and cancer.
[pyometeria (pyo) = infection to the point of the womb being pus-filled. Often used as a catch-all term for vaginal bleeding on the forum]
I would have her spayed in the next couple of days. Sometimes a strong course of ABs can cure the problem, but in something like 80% of times the rat ends up needing to be spayed anyway. And in my opinion it's better to spay when the problem first appears and the rat is stronger than waiting a week or so while the rat gets weaker. ABs are also only going to be successful if it's an infection where no pus is present (pus can be there and not emerge), and you can't tell the cause without opening them up...
Do you know what your vet is like surgery-wise?
I don't quite know how you'd diagnose a rat with high blood pressure, but from the diet she'd been on it may have been higher than usual. Either way diet won't be the cause of this. Well done for noticing.
I'd pop her and a friend in a low-level hospital cage tonight with something yummy and keep an eye on her. And then take her in to the vets first thing tomorrow

*~~Beri~~*
with
the ratlings: Orbit, Lanorial, Amdridh, Arkiadera, Esker, Brie, Larka and Foxtrot. Also Anfreda the hamsterling.

All those who've moved on