We have two theories about why she regurged.

Mine is that it's because I handled her too soon before her shed (which makes me feel like the worst snake mommy ever).

The man we bought her from says it may be because she was cold, since she she shouldn't have had anything solid to regurge so close to her feeding date. We did have an unusually cold week, but we added a heating pad over her tank and she spent a lot of time on her cool side.