Your niece.
Your brothers ( or sisters ) daughter is your ( niece )
Your brother or sister's daughter is called 'your niece.'
They are sisters in law.
My brothers-in-law are my sisters' misters. I don't know which of the sisters' husbands he is.
If she is your sisters daughter then she is your neice :)
Well, it depends how close you are to your husbands family. If you really want to know they are cousins-in-law.
spain
yes
she would be your grandmals sisters sons daughter =)
She is your niece.
brother in law
Its would be your neice