What are some signs of a good first interview?

It is a good sign that the hiring manager had you meet her boss - especially if this was unplanned. It shows that she liked you. It would be fine for you to send a brief note (email is fine) to the hiring manager and human resource person responsible for the interview to reiterate your interest in the position. A phone call would be even better. In the phone call it is okay to thank them again for the interview and tell them the reason you are calling is because you are very interested in the position and know that it is a great fit for both of you. Then ask what is the next step and what you can do to get the job. Then end the phone call - short and sweet. **As a human resource professional I can tell you that letters and all that fluff don't matter one bit to me. I rarely even read them. The only comment that I would add is that sometimes hiring managers do and say things that have very little to do with the reality of the situation. They do this because they are uncomfortable giving straight talk when the message is less than positive. That doesn't sound like the case here. I hope you get the job.

Yes, that's Normal. Interviewing is a numbers game. When the boss/supervisor of the interviewer interviews a candidate that usually means that you are one of the finalists. Now it depends on how the company operates, but they might have someone better or might want to look at some more people. Here are some things to be concerned: "She THOUGHT you would be a good fit". This might mean that they are not completely sold on you. Did you close the interview or did they, and did you close them to hire you? What I would do is follow-up with the interviewer and the interviewer's boss, with an email, phone call, etc; to show that you are still interested and the you have good follow-up, and are diligent in seeking this position.