Stanford will only consider your parents when determining “legacy” status, not other relatives who may have attended Stanford (although if your aunt and uncle donated lots and lots of money, that might make a difference, because they do consider your family’s donor status).
You are a strong student with some great ECs, and it’s certainly worth applying to Stanford REA. Of course it’s a reach… as I’m sure you know, there are lots of very strong students in the Bay Area and they can’t admit all of them 
Make an effort to apply EA to all public universities on your list that offer this option, as well as any private ones that are allowed along with Stanford REA (due to having early merit scholarship deadlines) such as USC. Some public universities accept the majority of their class in EA, or may run out of space in popular majors, etc.