Hello,
I heard often that Diana is ranked as the most powerful etc. female in DC.

But:

1. I am sure that Power Girl is phsyically stronger than her and Diana wins because she is sligthly weaker, but WW is better trained and has more experience.
2. There is Elaine
3. I think Secret may be more powerful than her
4. I think Raven is for sure more powerful than Diana, but restricts herself