We have labels for people which describe who they are to us. I'm pretty sure I have every possible relation possible in my family. In my family we have just about all of the labels I can think of. We have:
This doesn't include the cousins by marriage, by blood, by nature of being someone's mom's best friend's kid etc. Oh and then there is "Uncle Brother". That is what we all call him. I'm not actually sure how we are related. If I remember correctly, his nickname was "Brother", so to many of us he became "Uncle Brother". Not as twisted as it sounds.
Growing up in Hawaii our family was our Ohana. Being related by blood was not a prerequisite to being part of the family. You either were Ohana or you were not.
I didn't grow up questioning how I was related to so and so, I just knew they were part of our family. There is a saying, "Blood means you are related, it doesn't mean you are family."
My step-dads, and yes that is "dads" plural, not as in the I have two dads way, but in the my mom was married four times way, my step-dads brought even more family into our Ohana over the years. For me it was perfectly normal to have multiple sets of grandparents.
My second step-dad was the father or my first step-dad. Wrap your head around that one. The nice part about that was our family life and holidays didn't change much, beyond the fact that our grandfather became our step-dad and our step-dad became our step-brother, the rest of the family stayed in place.
To minimize confusion, we decided to have everyone maintain their titles. So, our grandpa was still called grandpa even though he was married to my mom. We always called our step-dad by his name, so he remained Brian. Crazy I know, but we made it work.
There are five children that I've raised or am raising. I gave birth to three of them. Today, the three are adults. My younger two are still school-aged and experiencing step-siblings for the first time and they love it. It was their idea to introduce me to people as their step-mom. My partner in life, love and laughter is their father, Tony. Oh, and Tony and I aren't married.
You would really need a diagram to understand most of this. The reason I'm sharing it is because my experiences in creating and maintaining a very blended family are why I think I can give you advice on doing the same.
I'm not saying everyone should have the same relations and dynamic as my family. I'm saying that if I've been able to make most of this work, most of the time, I just might have a few wise things to say. If nothing else, your blended family or your mildly dysfunctional family for that matter, might sound much more normal than you thought it was. Oh, and did I mention I grew up in a cult? Most of my family growing up were members of the Church of Scientology until 2010, but that's another story.
My siblings and I. Not half, not full, just family!