This is an absolutely amazing idea! I personally would love to write more on the relationship between Snape and Ellia, and how Snape would react to being a grandfather. It would either be an exchanged life for life spell or it'd be something to do with Ellia and Dracos son Scorpios. However, I'm in college now and have barely anytime to write, which saddens me a lot because I love writing, so it's unlikely that I'll publish a 4th book. But I will let you know if I change my mind. All the best x ✌