are there laws preventing immediate family members that are employees from filing for unemployment or tdi?

Huh? Whose immediate family members are we talking about? Everyone is an immediate family member of SOMEONE.

As long as they were treated as employees, no.

okay-the scoop is my husband & brother in law run a seasonal business they don't both need to work in the off season-one can run the show. can the other be laid off even though he is a partner? thanks

Doubtful, but let me do some research to confirm my initial response.

And, if you'd provided the "scoop" in your original post, I might have had a different answer. ;)