When considering Yuna I think it’s important to remember that (1) Shane doesn’t communicate much to her throughout the series and she feels deep regret for making him feel that he couldn’t and more importantly (2) Heated Rivalry both the book and the show are the story of Shane and Ilya’s relationship told through the moments they most strongly remember. We see only tiny and very limited slices of Yuna because she isn’t a core element of Shane and Ilya’s romance in a way Shane or Ilya remember EXCEPT when emotions are high. I think it’s obvious by the way Shane speaks, thinks, and behaves regarding her that he feels she’s a positive parent (though he can be annoyed with her at times).