On many occasions, ever since the OKW units were being built along the canal, this 'ole fisherman has tossed a jig into the canal and brought in bass, bream, catfish and sunfish. They all go back, of course, just like we do with their big cousins when we're on the flats or in the rivers.
A small 1/8 -- 3/16 oz. jig with a short plastic worm bounced along the bottom will probably get their attention. On cloudy, windy days you may to to toss a topwater crankbait. The area behind the swimming pool around the OKW 50's buildings is a good place to get down to the water.
As to whether it's allowed or legal, I really don't know. My fishing was usually early in the day or late in the evening, while family members were getting ready for the day's or evening's activities. I can't imagine the powers that be preventing a Dad from letting his kid get a fish, however.
Remember the adage from an old Sarasota, FL fishing guide: "Take a kid fishin', because someday he may take you." It was true with me and my Dad, and it's worked with me and my son...so good luck, and good fishing!