The only reason someone who has fifteen years of experience would actually have a "supervisor" is he/she was working in a clinic or hospital setting. A therapist in private practice, who has met the requirements for their "clinical hours" leading to full licensing, doesn't have a supervisor. Those individuals have exactly what she told you she has: her own therapist and a peer group of fellow therapists who provide "peer supervision or consultation". I'd be more inclined to be worried if someone is in private practice and she said she didn't work or consult with ANYONE because she's through with all that stuff.

The other thing is that a well seasoned therapist who works in a clinic and/or hospital probably IS the one who is supervising less experienced therapists. If she has a supervisor in that setting it would probably be the clinic director and that person wouldn't probably be doing weekly supervisions sessions with the seasoned clinician, it would be more "clinic related issues" like who is up for the next admission, who needs to go for training etc.

As for the "warmth" issue, I have interviewed a LOT of potential therapists and some are immediately warm and fuzzy and others are a bit more reserved. I don't know about you but I can't always tell if someone is warm or open until I've met with a few times. Those initial few meetings are often uncomfortable or at least stressful for both the new therapist and the potential client--after all, neither of you are sure if you're going to make a good solid connection. I say, give her a try. The thing you mentioned that was very important to you was to work with someone who was seasoned and experienced.