Loki picks up her scepter and tap-tap-taps away.
When no instruction on magic from Father is forthcoming, she starts - unobtrusively - reading about magic in the library. It is not very instructional, but it is something. She takes notes. These are partly in plaintext - she would be in some trouble, if she were discovered, but that's more likely to happen at the reading stage than at the note-reviewing stage. Partly they are in her cipher, which she uses because not only is she uncertain of Thor keeping her distance from the private notes, but also she is quite certain that Heimdall sees everything. (Her processing notes are not even in the diary-and-planning cipher; these she has learned to do in code that not even she can read an hour later.)
When she has gotten through as much as she reasonably can without outside help, at her current reading level - years later - she seeks her father again.
When no instruction on magic from Father is forthcoming, she starts - unobtrusively - reading about magic in the library. It is not very instructional, but it is something. She takes notes. These are partly in plaintext - she would be in some trouble, if she were discovered, but that's more likely to happen at the reading stage than at the note-reviewing stage. Partly they are in her cipher, which she uses because not only is she uncertain of Thor keeping her distance from the private notes, but also she is quite certain that Heimdall sees everything. (Her processing notes are not even in the diary-and-planning cipher; these she has learned to do in code that not even she can read an hour later.)
When she has gotten through as much as she reasonably can without outside help, at her current reading level - years later - she seeks her father again.