I always think it is good to give feedback to professionals, including negative feedback. In principle, someone intelligent and knowledgeable in their field and associated expectations should be able to see their own strengths and weaknesses, but in reality is far from that simple. I also think that good constructive feedback can motivate many people quite effectively to develop themselves. Of course no one actually likes to hear negatives but it is a way to raise awareness and remember it since often people tend to quickly block out negative perceptions even if they have fairly objective ones about themselves. Giving a professional feedback can be a form of performance appraisal, and service providers are pretty much the employees of the clients they serve, even if the client does not pay them directly but an agency pays for it. So I would not feel bad about the critique for a second in a way that I offended her, if the feedback was fair and based on your experience!

And I agree with here today - someone with a reasonable conscience and desire to do well should not react to criticism by making things difficult for the critic behind the scenes. If she does that, then I would say she has much more issues to work on than just not being competent to provide therapy yet. Of course many incompetent and insecure people do just that, but it should not reflect you and and feature about you, more how their own passive aggressive and shady approach.

One thing I wondered reading the OP - why is it necessary to rely on someone like this nurse to find a new therapy provider? I am not familiar with the public healthcare system in Sweden - do patients have no choice in who they see, you cannot approach the pros yourself for your needs? If that is the case, I understand. I grew up in a European country that had that sort of healthcare system during my time and we could not even freely choose a GP, let alone specialists. That's a bit like when someone is job hunting and relies on formal connections, letters of recommendation etc. Not a very wise idea to offend someone with power in that situation.

I think it's hard to predict how this nurse will react based on some posts, without knowing her and how she handles her business, and even knowing someone quite well, it can be tricky to guess how they act behind the scenes. Given what you said about her "abilities" I wonder if she is a good person to refer you to other professionals with good skill and integrity? I personally think that no therapy is better than bad (or even useless) therapy.