This is a tricky one as melancholy often involves a sort of visible weariness that manifests in limited, often jerky, gestures and short, stilted speech. Still, I'm nothing if not keen on a challenge.
Of course, since I'll be throwing out examples of sadness, let's get the obvious one out of the way:
1. Jane cried / wailed / keened over her tiara.
Now onto the less obvious methods of showing sadness.
2. Jane slouched into the room and headed into the living room.
3. She slumped into the couch.
4. "Sure. Sounds great." Her flat tone and drooping shoulders showed she thought it would be anything but.
5. Her eyes welled up in tears as she stared down at her feet.
6. She didn't bother to look at him. What was the point?
7. She plastered on a tight smile. "No, really, I feel better now," she said a little too loudly. "You can stop, really."
8. Her lower lip trembled as she struggled to blink back the tears before they dripped down her cheeks.
9. She lowered her head into her hands, shoulders shaking as she fought back the grief.
10. Jane leaned her head against the window glass, staring outside but seeing nothing.
11. She tried to clear her throat, but the twisted lump remained, drawing her voice tight over every syllable.
12. She clenched her fists, quickly drawing in breath, hoping the feeling would pass.
13. She rubbed at her chest, trying to ease the ache in her heart, and gulped for air. It was so hard to breathe.
14. "Where were you?" Her voice broke over the last syllable.
15. Her breath caught in her throat. "Simon?"