https://www.youtube.com/watch?v=Ah-MELvV86g
Watch this, it will be right in front your face.
Show me, with this footage, how weak she is compared to Supes. Show me where she lacks super-strength, endurance, stamina and speed. The only power that is not shown, or at least ambiguously shown is flight.
But what we can say for sure with this footage is that she has super-strength, super-speed, super-athleticsm, stamina, durability and good fighting abilities.
Analysis:
- Super-jump and super-speed: If she was so much slower than Superman, then why didn't Superman outfly her and get to DD first even when flying off after Wonder Woman jumped?
- Super strength: She shield-slammed Doomsday and sent him in the air quite easily. After that, Supes punches Doomsday in the face and it did nothing to him and he got thrown away like a ball. She also easily dealt with the car sent onto her by DD. Try doing that with a bag of the same weight as your body weight without being pushed away, try it and you'll see how powerful WW is.
And then, in that scene where she stops a full punch by DD with her sword, it indeed takes a huge amount on strength to withstand it, you can even see the wind generated by the shock and you can see the struggle in Diana's Face. She also successfully lassoes Doomsday, revealing that her might is huge enough to keep DD from breaking off.
After all this, show me where she is so much weaker than Superman here?
EDIT: After Supes is kicked away by Doomsday, WW uses her shockwave attack at Doomsday, makes me think that she might have done that in order to repel Doomsday away from Superman, the same way she did that with Batman when she saved him from his laster blast.