Last of the immediate family.
BIL - I am thankful that you are not afraid to keep it real or tell it like it is. Sure you might be gruff and abrasive, but it's also part of your charm. I am thankful you are a man of character. You can be fun to hang out with. I am glad I am getting to know. I might even say that we get along, I am thankful for that.
SIL - I might as well just drop the IL. You are more like a sister than a sister in law. You have been through so many things that I am going through it is nice to have someone to bounce things off of, vent at or listen when you have hit your limit. I love hanging out with you. We laugh like crazy. I am thankful that BIL came to his senses and married you.
N - Oh boy, I am thankful you are our nephew. You are a funny little guy. I can already see that you will be a great cousin and watch out for Kaitlyn.