How to annotate adoption on a family tree?

[DonutCone]

So DM is adopted. I'm doing my family tree on Ancestry. I don't want to put her adoptive parents down on the tree without annotation as biologically they were not my GP's and to my mind that is the entire point of the tree. I'm tracing my genes back through the generations and I'd be pissed off if I found people had listed adoptive relatives as my relations when they weren't IYSWIM.

On the hand hand, I love my GP's! I didn't know her biological parents as they died before I was born. So I don't want to completely airbrush them out. But I'm don't want them listed on my tree as my actual GP's as it feels weird to then start listing their Grandparents, whom I didn't ever meet or have a relationship with as my relatives when they weren't. It feels different with the people I have/had a bond with as they became my family. But people who died 200 years ago, I just feel really strongly, aren't

Anyway, has anyone had this issues, what did you end up doing? Can I put 2 sets of parents in for one person and just annotate 'adoptive parents' but then just not trace their lines back any further?

I had a similar problem with my tree on Ancestry. My brother was adopted by my parents. I put down in his notes section that he was adopted in 196?

I did another tree, you can do more than one tree on Ancestry, for my brother, using his birth name and I was able to trace his mother's family back to 1841. We only have his mother's side as we only had her name and details.

I thought family trees were biological therefore you’d put actual parents not adoptive parents.