Tsunade is a great character she just needs more development and some other skills. She is strong and her faith in Naruto really helped Naruto to gain power. Her healing abilities are unrivaled
and her strength is awesome I think if she was forced into a battle with an s-class shinobi I doubt that she could loose since she is smart as well as strong.
Her grandma was the 1st Hokage's wife and Kushina was 4rth Hokage's wife. Both of them were top, top, TOP secret Jinks in Konoha. Only Sarutobi, his wife, Minato, Elders and very few ANBU knew about it! And if it was such a top secret case it means there was no documents about it. Just like there's no documents about Naruto being Jink. And remember one thing - Tsunade wasn't the Hokage until she met Naruto but still she knew about him being Jink. Jir wouldn't say a thing if he was told not to. And I'm sure he was told not to talk about it with anyone becuase it would put Naruto in grave danger.
Tsunade will have her battle. And she will kick some ass. Until then, people really need to stop assuming that she's weak. Until we all see her in a REAL battle when she goes all out, assuming that she's weak, when Kishi says otherwise, makes you all look like little fanboy kids that just have nothing better to do that to bash a character that's drawn on paper in a Japanese manga.