Libby has always written Bulletgirl with the same physical powers as Bulletman, and noted that she had a drink of Jim Barr's anti-crime potion. I've read her bio on a half dozen web sites, and several of them specifically state that she does NOT have powers. But, here is her origin story:

and here's proof that she really DOES have powers.

I added a 'mental' power for Sue to match Jim's increased intelligence, 'enhanced intuition', in The New Adventures of Bulletboy, Chapter 9: Side Effects

"Jim smiled. “There seems to be some kind of random effect that may alter the physical appearance of the one who takes the drug. Overnight I grew several inches and gained more than forty pounds. But Sue’s appearance didn’t change at all. I’ve never quite figured out why it affected us differently. Of course, our circumstances were a little different. I was scrawny and out of shape when I took the drug. But she was already a superb athlete in tip-top physical condition before she actually used the drug herself and became my partner as Bulletgirl.”

Susan Barr had been leaning forward, listening carefully. She sat back with a smile, snapped her fingers, and announced, “I’ve got it!”

Jim kept talking. “Not to mention the mental changes. I had always been very logical and ‘bookish,’ and pretty smart. But afterwards, my logical thinking and deductive abilities had been vastly enhanced. On the other hand, Sue was always very intuitive, and the anti-crime drug seems to have vastly improved her intuition. She is simply amazing at coming up with the right answers without enough information. You would be astounded at the number of our most difficult cases that she has solved right up front, and the rest of the case was simply us looking for enough information so that I could prove she was right."