How to RescueEdit
Switch to Juliette via the Telepoint near the bookcase if you have not already done so. Climb the wall via the Cat Scratches on the bookcase. At the top shelf, leap over to the other shelf, then jump onto the chair. Leap up to the two buttons and press them.
When the chair back has risen, climb up the Cat Scratches to the top. Now, leap over to the Piano and switch to Tweek. Now Glide around the corner to the plants on the table (not the one on the shelf!) to rescue Yweek. Remember to land on the pot itself!