My sister was a phlebotomist for many years and then went to school to become a nurse. She worked very hard in school. (She also worked part time for the first couple of years and has 3 kids to raise, which did not make it easier.)

She now works at a hospital in a post-surgical critical care unit. The days are very long -- 12 hour shifts. She's looking for a new job that has better hours.

My cousin also became a nurse as a career change when she was in her 30s (and was the mother of 4). Again, worked very hard in school and her first job in a hospital involved long shifts. But now she's at an outpatient surgical facility and she seems to like it.