How powerful is Black Canary?

She has a scream that is powerful enough to destroy some metals and cave in people's skulls (she does this to Roy Harper when reality is being tampered with by Anansi). In addition to this, she is one of the most accomplished martial artists in the DC universe.

Her thighs could snap a mans neck.

@Xanni15 said:

Her thighs could snap a mans neck.

but unless that man is gay, he would welcome such death

but good question, what's the highest durability character she can skull blast with her scream??

She kicks people in the nuts.

Let's see...

New Birds Of Prey first appearance - Destroyed a boat

After some time - Claims that can turn people brains into jelly

Some weeks ago - Destroyed a huge build.

Birds Of Prey #9283118723 - Destroyed Canis Majoris