We don’t know? Sirrian has stopped writing lore for now.
Doing some digging on the matter, Skadi came out while Sirrian was still writing lore for weekly troops and had this to say on the matter:
Others tell tales where she was the first Fey of the Winter Court, and Queen Mab is her direct descendant.
Given that Mab is Skadi’s descendant, and that the “daughter” is clearly younger than Mab (they all possess empowered eyes), the timeline is more accurately:
Skadi (mythic) → [unknown number of generations] → Maeve (unknown) → Mab (legendary) -->; Mab’s Daugher (epic)