Heidi continued stealing glances of her own, against her brain telling her not to. Tracey was straight, surely. Even if she wasn't she still was sure to hold no interest in a girl like Heidi.
As Tracey took her hand once more, Heidi forced herself from not letting her eyes shut. Feeling the warmth, she smiled at Tracey, "Thanks." she said before returning to focus on drying the powder.
After the powder was fully dried, Heidi made sure to measure the correct amount, then remeasure it to make sure. she held the powder over the cauldron and chuckled at Tracey's comment, "Here goes..."
Dumping the powder in, Heidi closed her eyes, hoping that there would be no explosion. When a few seconds passed, she opened her eyes and gave Tracey a brilliant smile. "No explosions yet. That's a good sign."