Dashboard load issues

So I’m trying to help my wife fix her site. The dashboard loads abysmally slow. Then once it finally loads, trying to navigate through the dashboard is also stupid slow, if it loads at all. Also, every time she tries to type a post or a new page, as soon as she hits save, the whole thing crashes out, losing most all of the work done. The auto save is only working intermittently as well. At least half the time you try to load a different section of the dashboard, an error comes up saying something about incorrect redirect. None of this ever happened until the upgrade to 3.5 I did last week. Any ideas?