u/OfficialLilUnderdogg

1. Obviously we know she could turn evil because of the leaked dolls.
2. In the Mad (Wicked Wonderland) song, Chloe/Malia sings a specific lyric that says "Got some tricks up my sleeve and a watch on my mind And once I get what I want, all the power is mine" and references the Pocketwatch having to do with it.
3. Some fans having been saying that during Chloe and Max's duet (Heartless), Max probably tries to hypnotize/convince her to turn evil in some way or gives her a potion that does the same thing (cuz if you play the whole trailer in slow motion, you can see Max working on a bunch of chemicals).
4. If you look in one of Chloe's Promo Posters for D5, there is an Easter Egg that says "Beware The Jabberwocky", meaning that she summoned the Jabberwocky or has to slay it.
5. Chloe might turn evil because due to her and Red changing the timeline, Chad probably cease to exist and Chloe might want the watch to prevent it but Red disagrees because she likes her new life (reference to my 2nd theory).

Zoom in at the bottom left corner of Chloe's Wicked Wonderland poster to find it. It will say "BEWARE THE JABBERWOCKY".

HERE