Homestuck's bandcamp mucked up and rearranged (and hid) a bunch of tracks a while back, and I don't think anything is missing, but...
Official Soundtrack
Volumes 1-4
Classic early Homestuck tunes. The original Jade leitmotifs!
Volume 5
Not... technically sure if Greenhouse is explicitly a Jade theme? But it obviously is. And I have feelings about that.
Volume 6
Medium
Some very pretty piano pieces. I've never actually listened to these, but they seem very peaceful?
Strife!
Aww yeah twangy strings AND guitar. She is Shredding.
Volume 7
[S] Cascade. You know the scene.
Volume 8
Volume 9
Okay so A Taste For Adventure is technically more of a Jake song, but it's got Dissension in it! I think she could have a good time with that one!
coloUrs and mayhem: Universe B
(Yes I know the cover art is wrong. Remember what I said about the bandcamp getting mucked up?)
Volume 10
Fansongs
RosieLord
A nice melancholy song for Jade. The artist has songs for the other beta kids, too.
horizon
Flare 「lyricover redux」
Not strictly a Jade song, but plausibly, and she's on the track art. It's a Jade song in my heart. :)