"Fixing" feet of an adult horse can lead to more problems than you had to start with. As long as she's not knocking her legs or tripping a lot, you should not try to fix them. Just keep them trimmed or shod based on the balance of the foot.
I wouldn't do a lot of jumping with a pigeon toed horse, but if it's mild, some light small jumps would likely be fine. I would ask your vet and farrier for their opinion though. They will know your horse and be better at assessing her capabilities.