I don't really know much, but I know Enna and her mom have a...complicated relationship. I know that her mother has a plethora of mental issues and Enna has a hard time dealing with her around this time. Recently she's been trying to get in touch and be more accepting but...that has some mixed results. Regardless, the situation is rather complicated and knowing Enna, having Fulgur laugh at it is most likely the reaction Enna would want out of it.