Take her to the doctor. The wee accidents could be related to the poo issue. DS has a distended bowel and it has taken from three years old until now aged seven, to final start to get somewhere (sorry). The distended bowel was caused by his holding poo when he was in nursery as he wanted to play, not go to the loo! That built up, made his bowel sloppy and so the poo built up and round and round we went. The poo in the bowel then leaned on his bladder causing the signal to wee to weaken so he would wet himself too.
He went on movicol which helped and he has been dry for three years but we cut it back when he seemed to be improving and he got worse again. When he started school he was being changed five times a day at a minimum. He now soils perhaps once every five to seven days so we are getting there.
We have a game of sitting on the loo and blowing up a whoopie cushion. Blowing a balloon or party blower works too as it mimics the push you make when you poo, but the whoopie cushion is more fun because of the rude noise you make each time you deflate it. If you ask kids to push they tend to suck in their tummy. But you try the poo push...you actually push your tummy out which pushes down on your bowel. So blowing makes the same action. Sitting for ten minutes about 15 to 20 minutes after each meal, rocking forward (I get DS to try to touch his forehead to my hand held about six inches in front of his knees but at head height), then rocking backwards and then blowing. Keep it going for as much of the ten minutes as you can. Don't worry if the poo doesn't come every time but it trains the poo to move down the bowel and makes DC feel it coming. DS never runs to the loo needing to go but will go within a minute or two of sitting down now.
He also has two spoonfuls of senna every other day, on doctors orders, as the distended bowel meant he gets no signal that poo is coming so the bowel is sluggish and the senna does the work. He has one movicol every week day morning and an additional afternoon movicol at the weekend.
ERIC is a great website that gives lots of tips.
Movicol works well but you do need to alter doses to suit the child and need about three to four days between any changes as it takes a few days to work.
Don't give up hope. DS isn't there yet but he tries really hard and it isn't his fault. We just work with him and, since we've accepted that this is the way it is and have made loo sitting into a game with rewards he has got better. DS loves getting cash now so we give him 10p if he poos on the loo, 10p if his pants are clean at the end of the day (if they aren't clean we ignore it, just help him clean up and say never mind), he also gets 2p if he has soiled but has told us as he has a habit of being so embarrassed that he doesn't mention it. He knows he should tell us or he will smell or get sore but he is so embarrassed and feels bad so we reward him for overcoming that. And of course we never never tell other people. If he soils when we are out it's a quick trip to the loo, change pants, chuck the others away and that's that.
He takes spare pants for his school swimming lessons in case he finds any soiling. We have spoken to him about how he can best sneak to the loo to clean up and change pants and he's very relaxed about doing that so his bottom's clean when they do the communal change.
It will get better but can take time. Your doctor may be able to refer you to a children's bowel and bladder nurse. Ours was helpful as she got the school to help DS a lot, to the extent that they got an additional TA when he started school to ensure he was taken to the loo as quickly as possible to get changed.