The first rule of potty training: you cannot attempt to potty train a child unless they are ready and show signs of interest in the potty. The more you try to force a child to potty train when they are not ready, the longer it will take and the more painful it will be for all involved.
I have potty trained MANY children, both typically developing and a-typically developing. Does your daughter show interest in the toliet? Does she seem to want to use it, or is she interested in it when you go to the bathroom? Does she tell you when she is wet or has pooped? If so, she is ready for you to start the process. Take her to the bathroom with you and let her flush the toliet when you are done - say "bye bye" to the poo poo or pee pee. If she seems interested in this, next time she has a bowel movement in her diaper, dont throw the diaper away, but take her in the bathroom and empty the poop into the toliet and let her flush it. If she seems comfortable with all this, ask her if she would like to use the potty - if she can not yet tell you when she has to go, this will be a long process.
Take heart that little girls are far easier to train than boys. Go to the store and get her one of those potty seats that has little steps and fits over the actual toliet (attached to the steps is a little plastic seat that fits over the toliet seat making it smaller so that she wont fall in or have to balance). This will allow her to start going to the potty alone when she is ready - stress the fact that big girls use the potty, and when she starts using it often, she can pick out any pretty big girl panties that she wants. Make a routine of using the bathroom - get her special toliet paper, flushable wipes, or foamy hand soap for washing hands after (Kandoo has cool soap and flushable wipes that toddlers love). There are also many childrens books out there at any book store that help introduce the toliet training in a way that a child will be interested in and understand.
Remember, dont push her to use the bathroom if she does not seem interested in the process. Give it up for a few months, and then try again.
Feel free to contact me with any questions you may have - good luck!