Welcome to WikiTree Bonnie
I have been for 25 years working on my biological, and adoptive families trees.
I have linked myself to my adoptive step fathers side of the WikiTree web by placing a box in the biography section of his profile.
https://www.wikitree.com/index.php?title=Elder-2333&public=1
The code for this which I found somewhere on WikiTree is;
<div style="float:right; border:2px #000 solid; background-color: yellow; width:200px; height:auto; margin: auto"> Children:
[[WikiTree ID|Name]]]</div>
<div style="clear:both;"></div>
Repeat the WikiTree ID insert for each sibling you might have with him as a father.
WikiTree wants us to link our biological parents to ourselves but also allows for us to note other significant relationships in the biography sections allowing linking to our other parents, siblings, etc.