I think that instead of superpowers she should become a bit like oracle. She could always be in Spider-man's ear and it would allow Spidey and Mary Jane banter throughout his battles. It would let her be a part of her life without giving her powers.
sagefire's forum posts
I've always liked the explanation that Krypton exploded a bit too soon for Jor-El and he was in the process of testing spacecraft. Sending off Krypto to test if a living being could make it to earth safely, and when that pod didn't seem to work he built another prototype. When the cataclysm started he only had his test probe, and that it was only big enough for the baby. I've always thought that explanation was the best.
I always liked the explanation that they gave in the 90's cartoon. At one point Peter said that after being bitten by the spider, he instinctively knew what chemicals to mix in order to create the webbing. I've always liked this explanation as peter only needed the engineering knowledge of creating the actual shooting device itself, rather than the chemical process.