Help!

Mom-to-be sister told me i need to get a flu shot if i am to be around her baby. She knows i do not get them as it is a choice i made a few years ago for my own health and others'. I request people do not say I am right or wrong as that is not the point (and this topic tends to garner that kind of discourse).I do not know what to do as my relationship with my sister is already pretty unstable. Help! Thanks guys :).