Sounds like my family.
On my dad's side I had a step-brother and step-sister. Step-sister had 4 kids. That's easy enough they think of me as a (very distant) aunt. Step-brother had three kids, two born 6 months apart the same year Chris was born. The first one "little" John thinks of me as an aunt. I can live with that. The second one, Mary was duped by the step-bro and his GF on my dad and step-mom who eventually adopted her legally, so she is legally my adopted sister (I think it would be half sister same dads different moms) and refers to me as her sister (ick by the way) but calls me "aunt." The third one, whom I have never ever met but who recently got in touch with the first and second ones now calls me "aunt." Yeah, ok.
My mom's side is even more convoluted. The niece that lives with me is my step-dad's, adopted daughter's kid.Her brother has an ex-gf who has a couple of kids who aren't his who think of me as their aunt. So my step-dad's adopted daughter's son's ex-gf's kids by the guy who went clinically insane (for real) think of me as their aunt and referred to Chris as their (first) cousin even though he would have been a second cousin or third, I lose track.
Butttt nephew and ex-gf have a couple of their own kids who still aren't any blood kin to me also. Then other step-sis, who is my step-dad's bio daughter had three kids, one of which my mom and step-dad adopted so he is legally my (full..same mom's) brother. I ca;; him my brother-nephew. He is married to a guy who is either my BIL or nephew-in-law depending on the day.
There's more, but I'll just leave this right here.
There are no steps, no halves and no adoptees in my family or 1st cousins. A handful of ex's but no kids.
At the 2nd cousin level there are 3 adoptees, one who I grew up with and the other 2 in Washington, possibly Seattle or Puyallup At my grandparents level, source of the 2nd cousins, my mom's mom was 1 of8, my mom's dad 1 of 3; On my dad's side, my grandpa was one of 9 and my grandmother 1 of 3. No halves, no steps living or dead.
It feels... dull