Jackie Said:

Is it easier to get into the Ivy League if you're already a graduate with a high paying career?

We Answered:

No. No matter what, Ivy League schools are selective. There is no way around it. Even if you held a job for 2 years, that counts as a mere extracurricular to them. There are people that get denied from Ivies that have published books, or studied abroad. While holding a job CAN help your application by representing itself as an extracurricular, it can't really do much else than increasing your chance by a small percentage.
And don't forget, there are always hundreds, and even thousands of people applying for a spot that are just like you (or very similar).
And it's not just the work experience that you have, it's other things like grades, community service, personality(shown in interviews), etc..

Nelson Said:

What kind of careers require short period of education but high pay like nurse?

We Answered:

Physical Therapist, Anesthesiologist, Veterinary Technician if you like animals with decent pay in large urban areas.