Thanks for sending me your save
I've had a look and unfortunately I've got some bad news
you were so ahead with so many characters that it has messed up the triggering of others, in this case being Kendra.
When it comes to this game, it is not very forgiving, as most characters are intertwined with others. The game is made in such a way that the characters aren't compartmentalised, except for the Billy path, you can't follow one character's path without doing another's path.
Plus, it looks like the introduction of Kendra got messed up somehow, as I can't get past step 445, because if I had been able to do 445-449 she wouldn't still be appearing at the park.
so I'm sorry to say, by concentrating on certain characters and neglecting others, i.e. Kendra, you have indirectly caused the game to breakdown.
And that is also why I always recommend following the walkthrough to the letter when playing this game.
So I'm sorry to say, I can only recommend two courses of action
1-Start a new game and follow the walkthrough to the letter
2-Have a look at my saves and pick one that suites you.