I have an employer waiting from USA which is an US citizen and she want to hire me as a caregiver.?

i just want to know how many percentage of chances i have to pass my at the embassy. I have been told that USA wont hire someone from philippines as a caregiver. i have completed my 6 months training. How is this possible that USA wont hire someone from different country even if I already have an employer. How true is this?