Having recently read close to 100 essays from students applying to my children's hospital (and spent about 25 years hiring students and nurses) ...
The cheesy stories and the fluffy "magic" stuff should occupy no more than 33% of your essay. A little of that is fine, but I want to see it backed up with some things that are more substantial. For example:
1. I want to see some intellect -- not just some mushy "maternal instincts" that are natural for young women to have that draw them to care for children. I want to see that you have used reason and intelligence to decide that pediatrics is the right choice for you. I want to hire intelligent, clear-thinking nurses that can master the complicated material they will have to learn to become excellent nurses, and who can clarify (and sometimes separate) their feelings sufficiently to navigate the complex relationships among the patients, their families, you as a care-giving, and you colleagues who are also care-givers.
2. I want to see committment -- committment to work hard, to work the unpopular shifts, to do the difficult thing, etc. I want to see a committment to be great -- even when that means you have to do things that you don't want to do. I want to see that you are committed to the job and will stay in it for more than a year or so -- even when it turns out to be NOT the fantasy job you dream about. In the real world, most new grads go through a challenging adjustment period (i.e. reality shock, transition shock, etc.). Many quit their jobs when the going gets rough. I want to see that you are committed to seeing it through and staying in this job long enough to resolve those issues. I am looking to hire long-term employees, not people looking for a brief learning experience before moving on to something else.
3. I want to see flexibility -- a willingness and ability to adapt to our environment, even if it is not the ideal world you fantasize about.
4. I want to see that you have experience with children -- other people's children.
5. I want to see that you know the difference between professional relationships with children and personal relationships with children.
8. I want to see some maturity and some evidence that you are prepared to succeed in the real world -- as indicated by all of the above.
If you show me most of the above throughout the application process ... then you'll get my vote. Given that I hire only about 10% of the people who apply, you need to be pretty strong to make it to the top of my list. But fortunately, there are enough students out there who DO show me these things and I hope you can be one of them for the hosptial of your choice.