It's not like Ran is the only fox lady in fiction, Sacchi. The original kitsunes and their developed forms, kyuubis and tenkos, already made it a habit to turn into beautiful women to trick humans. Besides, Ran is between 800 and 900 years old, not 1000. If she were she'd have seven tails by now instead of nine (kyuubi lose tails after getting nine until they end up with four, turning them into tenko). I doubt it's a reference.
Though the similarities between Sakuya and the first pet are indeed suspicious, and might be a more direct reference. Either that or it's a reference to Yumeko, who had blond hair and was also a knife-chucking maid.
