I figure after Cap #25 most people are thinking that Sharon is either working for hydra or is brainwashed by Zola. One scene that led itself to this theory is the shunning of Jet, where Sharon told everyone that jet was a spy, saying that she heard Zola giving Jet orders when she was captured; something no one could confirm nor deny since no one else was there. Of course this led to Jet forsaking Steve and the Avengers, a result Zola wanted all along, after all wasn't kinda convenient that Sam and jet happened to find her cell, and why the heck did Zola keep Sharon around anyway, surely it would've been a greater revenge on his enemy to kill his beloved? So there you have it I think Sharon's been brain washed by Zola.

And let's not forget the whole epilogue thing in that issue at the hydra castle! From that we gathered that the Hydra mole was at avengers mansion when Sam was revealed as the new Cap, that they would never suspect her and that she's known Sam for years.

pretty incriminating evidence all around

Also, in the last issue of Avengers, Carol makes a comment to Steve and Sue that they both got into bed with the wrong people. That makes me assume that it really was Sharon at the end of Cap 25. Regardless, I will be upset if Remender retcons her into a long term Hydra agent.