He is your cousin ny marriage once removed . Just call him by his name.
Mom
no you should not tell your husbands mom about his health
Daughter in law(
well i think you would it would be your mom i mean OK if your father in law had only one kid it would be your husband. and your husbands mother in law would be your mom.
Your brother would call your husbands sister by her first name. Or, "my (sibling's) sister in law.
you call her your daughter's husband's sister
Well, I call her Abigail, but different strokes, etc.
brother in law
Its would be your neice
Your cousin in law
we can call her as mom or aunty..... Or you could call them by their name, that's what I do.
They call their Mom Mommy or Mom.