Prepare the lavender water by adding 2 tablespoons boiling water to the lavender. Let steep for 15 minutes and then use a fine sieve (or even a paper tea filer) to strain it. You should be left with 2 teaspoons of liquid. Set lavender water aside.
Add gelatin and water to a small bowl to soften the powder. Set aside.
Add cream and sugar to a small saucepan on medium heat. Heat until the cream starts to bubble around the edges (about 5 minutes, it shouldn't be boiling). Whisk until sugar dissolves.
Remove from heat and whisk in the gelatin mixture until it's dissolved.
Whisk in the yogurt, salt, lavender water, vanilla, and optional food coloring (6 drops blue, 6 drops red).
Pour into glasses or molds. Chill for at least 3 hours. If you're going to chill it overnight, cover each container.