You know, I am NOT OK in any way with my husband talking to other parties about issues he is having with me if he hasn't already talked to me about them. I know the intent isn't there, but to me it feels negative and gossipy (or fearful that it means our relationship is not strong), and I don't want to be married to somebody who can't discuss things with me first if they are about us. I know it may happen now and again, but I hate it with a passion, I'm a private person. If we've discussed a problem but it's ongoing, of course him talking about it with friends I expect, him discussing our stuff with metamours - well if I like them and am comfortable with them, I don't usually mind, and there will be a point where I specifically state that I am OK with them being a confidant of our "personal business". If I don't know them at all, or they come across as judgmental, I will ask Adam to not talk to them about it if the conflict isn't directly affecting them too. I talk to my two best friends and my sister about relationship issues to varying degrees, but I don't want to color a partner's opinion of another partner with transitory feelings or issues.
Oddly, I have no idea if my boyfriend talks to his partners at all about me. He doesn't talk about them in any way that includes sharing with me any problems they might be having. Because he is married I don't feel like it's necessary to protect some "core privacy", and if he's feeling unhappy about us, I imagine he would talk to his wife & girlfriend about it before he talked to me. I just realized as I wrote this that if he started dating somebody new and I hadn't met them, I would feel unhappy about the idea of him talking to them about issues he was having with me without a verbal statement from him that he was going to do so. So that was a tangent...
Anyway, if privacy is important to me, I make sure to discuss what I want or expect from any relationship, and to negotiate what is or isn't going to happen in that arena so I can figure out if I'm willing to accept them wanting to share differently than I do. If I haven't asked for privacy, I don't get too upset when I find out stuff I'd like to be private is shared with others.
On a side note - I think it is easier when both sides are sharing somewhat equally. If her bf is sharing relationship troubles with her, it might be natural for her to disclose more about her relationship with you. You have every right to ask her to only ask for advice and feedback from friends, relatives, forums without a heads up. You have a right to ask for whatever it is you want, and that's where negotiation begins. If she doesn't want to abide by your preferences, you get to decide if it means the relationship doesn't feel "safe" for you, and what that means to you.
Happiness will never come to those who fail to appreciate what they already have.