It's fine. You did well. You didn't offer to save her. You really didn't offer to fix anything either.

Before you talk again, mull this over: You don't have to fix her situation, but you can ask questions that may prompt her to look for her own answers. You can also take this opportunity to give her some words of affirmation. I get this sense that she's starting to hit bottom.....anything about her that she's good at? Is there any way to drop in something like, "you've always been good at x"? Little words of affirmation and appreciation sometimes go a fair ways.

I know that many advocate not saving the cheater....but do consider this. When she's struggling, who did she call? When the sky is falling...wasn't it you she started opening up to? You can make a positive impression here. Don't be her savior...but you can be an ear. Give her a few kudos and she might want to keep contacting you just to get more. Let her hang up with a good impression of you...a warm and fuzzy feeling. Couldn't hurt to try it and see if it does you any good.

You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer