Considering Rarity has plummeted from the sky about three times in the show, I imagine even under the Cloudwalker spell she’d still be nervous in the air. But dating a pegasus - the pegasus that directly or indirectly caught her each time - makes it a lot less scary.
Shout out to sulpsulk who got this in my head after we talked about Rarity falling. xD I tried to find if was a word for the fear of falling but it seems to go hand in hand with the fear of heights [apparently there’s also “bathophobia” which I’ve found it mostly means the fear of depths, not exactly falling per say]