Thanks for all the replies. I gave her Motrin and massaged her legs with a lavender arnica massage oil then put warm rags on them. It took quite a while but she finally stopped writhing and fell asleep. Fortunately it didn’t happen last night. I stocked up on arnica cream and a natural antihistamine as well as an apple cider vinegar based tonic that’s supposed to cure leg cramps. Has anyone tried that?