The pros of being a model are the possibility of making it big and becoming famous, traveling the world, and making up to $10 million per year. Also, if you become famous enough you could use your platform support causes you believe in. However, it is extremely rare to become this famous and you need to work really hard and make a lot of useful connections early on. The lowest average salary of a model in the US is around $30,000 per year.
As for nursing, there is more schooling that is required which is a big expense for most people. However, once you are done with the school your average salary in the US will be $40,000-70,000 per year. I would say that the hard work required for this job is the biggest downside, but there will always be a demand for your job so there is much more job stability than you will find as a model.