Silvia's story is available right after the prologue.  The story will loop itself unless you get the true ending. There are two bad endings that can loop you.

To get Silvia's ending you need to answer (all the correct choices):

• It's going well
•  Interfere
• Sport (if you choose the other one, you will get bad ending)
• Fear
• Ask

(If your points are not enough, you will get the bad end 1 here. The story will start over.)

• Activities/Connections (either is fine)
• Secret

(If your points are not enough, you will get the bad end 2 here. The story will start over.)

(If your points are enough, you will get to see the ending.)