I see that you have gone offline so I will answer your question as best I can without any further information.
There are many reasons to have blood in the urine or bleeding from vulva.
We often think of an infection but also crystals or stones in the urinary tract, masses in the vagina, or in the urinary or reproductive tract or clotting disorders are possible causes. If she is an unspayed female endometritis or a pyometra are possible causes as well.
Are her gums and tongue white, pale pink or bubble gum pink? If they are nice and pink then she likely hasn't lost enough blood to make her anemic and that is a good sign.
Is she bleeding only when she passes urine or does the bleeding ever seem independent of passing urine?
If the bleeding is only when she passes urine then concerns would be a genitourinary tract infection, crystals or stones in her urinary tract, a clotting abnormality or a mass in her urinary or reproductive tract.
If the bleeding is ever independent of her passing urine the concerns would be trauma to her reproductive tract (rough breeding), a mass or infection in her lower reproductive tract, or a clotting abnormality.
She does need to see her veterinarian.
If she were my patient I'd start with a urinalysis with culture and radiographs of her abdomen to look at her kidneys and bladder for signs of stones and the size and shape of her reproductive tract. We may need an abdominal ultrasound to identify some urinary calculi and masses in her bladder or reproductive tract. If she had pale gums signifying significant blood loss then I would want to check her clotting function too.
If her reproductive tract looked fine or she was spayed, money was very tight and there were signs of infection on the urinalysis then an antibiotic prescription for 10 to 14 days would be reasonable to start.
If I saw lots of crystals or abnormal looking cells on the urinalysis I'd warn the owner that things may be more serious.
And I'd recommend a recheck of her urine at the end of the antibiotic therapy. If there was still blood then radiographs or an ultrasound of her bladder/kidneys is needed.
If she had a recent heat cycle and her uterus looked enlarged, especially with an elevated white blood cell count then odds are this is a reproductive tract infection and I highly recommend that she be spayed.
All you can do for her at home is encourage fluid intake to flush out her urinary tract and toxins in her blood stream from a possible reproductive tract infection. Add water or low salt beef or chicken
broth to her food or feed her canned food
to encourage eating and increase her fluid intake.
Give her ice cubes. Offer her fresh water frequently.
And make sure she gets out frequently to urinate.
If she is straining but unable to pass urine, is vomiting, runs a fever (more than 103F rectally), has a tense, painful abdomen with gentle pressure, or her gums become very pale it is time for emergency veterinary care.
Please let me know if you have any further questions.