If you are worried... soak her tush in some warm water... clean off the poop and trim the feathers if needed. You don't want the vent to be clogged, and it probably isn't... but better safe than sorry.
Messy backsides are often cause by mites or lice eggs on hte nearby feathers, which then catch and collect poop. If when washing, it feels gritty, that is almost certainly the cause. Use a dog or cat flea/tick shampoo with an insect growth regulator to thoroughly clean the area (shampoo needs to remain on the bird long enough to kill the bugs, so be sure to follow directions. Scrape off as many of the eggs and/or pluck feathers as needed. You will need to retreat at least once; read package directions for appropriate timing.
Is her poo normal or is it runny or a funny color? Had a hen with sticky looking white poo on her tail feathers. She didn't make it, but I'm pretty sure in her case at least it was an egg laying issue. The warm baths seemed to help her at first, so I would definetely try that if you haven't already.
it was sort of a yellowy colour at first but now it seems to have gone a dark black-brown
also...found some tiny worms by her nesting box...how big are the ones that infect them?...i think the ones i found may be to big(and do would they get worms if they eat them?)
i think i will get some of that shampoo as well sometime soon and give her a bath tommorrow
thatnks for the help by the way