How do I help Gerde?

Hint 1 of 9:

Did you try talking to her?

Hint 2 of 9:

I guess she's not very chatty.

Hint 3 of 9:

Maybe there's something else you could do.

Hint 4 of 9:

Wolfgang's tomb looks kind of dreary, doesn't it?

Hint 5 of 9:

Flowers always seem to brighten things up a little.

Hint 6 of 9:

Why don't you offer Gerde some flowers as a peace offering?

Hint 7 of 9:

Those roses growing behind the castle might just do the trick.

Hint 8 of 9:

Take the secret passage from Gabriel's bedroom to the back of the castle and
pick some roses.

Hint 9 of 9:

Return to the crypt and give the roses to Gerde.