Well, if we're adding in the Uncanny Avengers crew:
Havok: Lorna Dane/Polaris, Madelyne Pryor, Scarlett McKenzie (Havok and Wolverine: Meltdown), Leila O'Toole/Plasma (Marvel Comics Presents), Mutant X Universe Madelyne Pryor, Annie Ghazikhanian. "Possibles" include Mutant X Universe Elektra, and Betsy Braddock/Psylocke (Pre-Ninja, during the Australia days). Very slim chance of Alison Blaire/Dazzler. (6+)
Sunfire: None/Unknown - I vaguely recall a woman from the early 90's X-titles (in the storyline that introduced Mikhail Rasputin, but she died the same issue she was introduced in and I can't recall her name. (0? 1+)