Cousin’s unvaccinated child

I’ve been feeling unsure about an approaching situation. My daughter will be born next month and my cousin and her son will definitely come to visit. Her son is about 2 years old and has not been vaccinated. That’s their choice - really none of my business... but I feel nervous about her child being close to my newborn. Especially because there have been measles cases in our state (and even county) this year.

I just don’t know how to handle the situation. 😐🤷🏼‍♀️