Either, Have her talk to Draco about him being mean, because she keeps saying she’s upset, I think she is the type of person to act. Or you could have her defend the trio when Draco is teasing them, and then she could talk to hermione after she defends them, bc it kind of proves that she is not a mean slitherin, and then right after that could be a filler chapter where hermione helps her with reading and they develop their relationship.
Then you could have either the hogsmead trip thing, or filches cat is petrified.
Then the next chapter after the cat thing she goes into the chamber to talk to her father, or she goes to Dumbledore and tells him about the father chamber thing.
Next chapter hermione petrified. (And other ppl)
Then next chapter she tells the trio about the chamber discreetly without saying it’s her father.
Last chapter they go into the chamber together.
There now there are a bunch of chapters all planned out, you just have to add details. Where I have done spaces are each a chapter idea
That whole thing would be the next chapter of the book, I think it is a good place to pick up where you left off