My emails are being sent to my aunt and she has a totally different email address. WHY!!??

My GMail is being sent to my aunts email address and she has a totally different email address than mine. Well she has one part that's similar to mine but that's cuz we have the same last name. But it's also being sent to me as well so I'm not missing out on the emails. Plus it's a yahoo acct. How is that possible?