I would have her as the primary of an army for PvP. The first 2 are the only skills applicable to combat and the 3rd is better than the 4th (4th skill is for rallying forts which isnt her specialty anyways, better pairings for that). For a f2p player I would personally level her up 1st skill maxed, then 2nd skill maxed (At this point better than I believe all maxed epic commanders), then 3rd skill maxed then 4th skill maxed. Her first skill is amazing, insane debuff.
Buy her 3 sculptures from expedition everyday and open the 12 chests you get from extra expedition quests. Aethelflaed is the most friendly free to play legendary commander.
