If your greatgrandmother is his great aunt then you and he are second cousins, once removed to each other. Your parent is his second cousin.
As the mother has deserted the child the greatgrandmother is the legal guardian as no one else is there to look after the one month old.
Your great aunt is your daughter's great great aunt. Your daughter is your great aunt's great great niece.
The Yiddish word for great-grandmother is "bobe" (באָבע).
Your great aunt.
You Aunt is you grandson's Great-Great Aunt. Your grandson is your Aunt's Great-Great Nephew.
You granddaughter is a great great niece of your aunt. Your aunt is your granddaughter's great great aunt.
To your child, she would be a great great great aunt. If she is your mother's great aunt, that means she is your great great aunt, making her a great great great aunt to your child. I would just stick to calling her auntie or Aunt ______. :)
Your great-great aunt is your daughter's great-great-great aunt.
Your grandmother's sister is your great aunt
She is your Great Aunt in law!
You are your neice's aunt, your neice's children's great aunt, and your neice's grandchildren's great great aunt
Your Great Great Aunt