I want to ask my aunt  why she named her kid after me
Can you tell me about that?
Honestly speaking it's really embarrassing, my aunt's kid shares my same name
You shouldn't assume your aunt named her kid after you. Maybe it is a common name and a great name to have?
Nah she stole it.
It's wrong to make demands upon your family members. She doesn't have to give you an answer if she doesn't want to.