Why do some japanese people say the “ee” sound as if it was an “ae” sound?

I have a friend who is Japanese and everyone in her family makes the "ee" sound like and "ae" or an "ay". I don't know it it's just her family that does this cuz I don't know many Japanese people apart from them. Some potentially useful context: She came from the Queens (NY) area and before that, she lived in Saitama. Plz tell me if I'm delusional.