I am currently in the state of applying for postdoctoral position after completion of PhD. I am being offered by my current PhD supervisor to do postdoc with her upon completion of PhD and after securing research grant. However I have a mixed feelings regarding continuing postdoc with her. My current supervisor has pros and cons attitude in research.

1. She has always motivated me to continue my PhD study whenever I felt like I wanted to quit the program.
2. She's a very nice person who understands the plight of being a researcher. She understands if I had to repeat the results etc.
3. She also understands if I had personal problems to attend to.

While she has above attitudes, there are some cons regarding her as well.

1. She always takes a lot of time to review my manuscript for publication purpose. One time, she took exactly one year just to review the manuscript for publication purpose. This has significantly reduced my publication number.

2. She is not an expert in the field. I struggled a lot throughout the PhD journey because most of the time she didn't know the stuff I'm talking about.

3. She isn't open to new ideas for research. She likes to play safe and only research what people have done before. She also doesn't open to the idea for collaboration with other researchers for publication in high impact journal. She likes to control everything and doesn't let me explore the ideas by myself.

4.She didn't stand up for me whenever I had problems with faculty members/ whenever I had conflict with university. One time a faculty member accused me of stealing materials in the lab and although I had denied several times I didn't do it, she made me apologize to that faculty member. The event tarnished my reputation and made me so stressful to be in the department.

is she a good supervisor?

I think she sounds like a very good supervisor! You were lucky to be honest! But that doesn't mean you should do a postdoc with her...

At a recent advice session/seminar for early career researchers, I heard that by sticking with the same people throughout it can appear that you actually are not independent (even if you are in reality)... and that you should aim to demonstrate your success in a different context/with different people post PhD. This may even mean suggest moving institutions. The point you raise about her liking to control everything and not letting you explore ideas for yourself is making lights flash as well - for the same reason outlined here. I reckon you should try to move on : )

i'd explore other options too, for the reason Tudor says above, but also because you said getting a postdoc with your current supervisor is dependent on her getting a grant, and we all know how that goes...

She would bee a good friend, but as a supervisor she is terrible.

She looks like she's very okay for PhDs and not okay for postdocs. Safe research is what you want to do at your PhD, it's the postdoc job to disarm landmines. If I'd were to guess, she's one of the younger in the staff and has no power to stand up for you when the senior profs are involved. She might understand that you want to try somewhere else, because if she understands the plight of a researcher, she also will understand you want to boost your career by changing the focus and going to different places. She might even offer help if you do explain it nicely.
Now a word of warning, most of the time it's your job to know the details of your project, and most of the time supervisors don't know everything. It's also good if they don't, because it's a sign you are becoming a specialist in your area.