From a plot POV it would be the most incredibly stupid development in the Naruto storyline if Kishi made it so. Most of Konoha villages knew Naruto as the 9 tail host and it's the reason why Minato was killed and she had a hand in naming him. She couldn't have been that oblivious. Kishi would have at least gave her a panel where she looked concerned when the 9 tails host was brought up to foreshadow a connection but that never occurred. Mizukage not confronting him for his own 'protection' just doesn't sit well. There's just never been a hint that she's alive from the people that would know the most of Naruto's parents.
I think it's just a case of similarity like the AL silhouette = Minato.
I think it's just a case of similarity like the AL silhouette = Minato.