Item #1 on the checklist: take a nice long walk through the orchard together, listening to her talk about how different everything feels to have a big equine body. Work up the courage to ask how her mouth feels, and then clarify what you meant. Take part in a cooperative experience while staring deeply into her eyes, amazed that you were able to find a girl like this.
Item #2: Jump up onto her piggyback style when she least expects it and get bucked off. Apologize for making her bray involuntarily.