Can I just say the the toilets in the arena (at Reading, not been to Leeds) really aren't that bad. So if you are in the arena all day you should be fine. They are the actual toilets in a caravan type.
The campsites aren't as nice but can normally find some nice ones.
If you are working, depending on what you are doing you may have access to staff or guest/press toilets.
Back to the shewee, there are female urinals which again need some practice at home first but quite easy depending on what you are wearing. (Jumpsuits are a big no-no!) and this area you can normally see the other women's bums as they are facing the urinals.