K.,
don't give up now. she needs to be potty trained and if you back out now, you will have to start again some day. Why delay?
here are a few tips:
warm weather just around the corner...no more pullups. none, not even at nights, not when you're out, just get rid of those. They're fancy diapers and feel like diapers.
Get to target get those thick underwear, potty trainers or whatever they're called. also target has mattress protector for 24.99. get that too. get a few portable potties and place them in all bathrooms that you have. get a portable potty with a lid (no music, nothing distracting, just a simple one with a lid on). place a container with wet wipes next to it. Tell her what it's for. Dress her, esp. at nights, with easy to undress jammies. and get started. you explain to her what she's supposed to do, and that's it. rewards didn't work for my twins so i quickly learned to just present potty training as a fact of life.
when she does go in her panties. let her stay like that (hence the warm weather, so she doesn't get cold or something). allow her to start getting uncomfortable. eventually, she will hate that feeling of wetness and dirtiness.
it should take about a week if you do not use pullups. i know, and i did too, dread the washing of everything all day every day. but, for me at least, and my twins, we did that for 1 week. after a week they were done with it.
one more tip. take her potty before bedtime (nothing to drink, except a bit of warm milk if she says she's thirsty) before bedtime, at least two hours before bedtime. then take her potty after brushing teeth. and then when you go to bed, assuming 10, 11 pm you go in and take her potty again. i still do that with one of my twins even though at this point (almost five, it's just a routine for me. i doubt she needs it). but every night, before i head to bed i take her potty. she's totally asleep yet she goes when i put her in the potty.
also, there is a potty that uses ziploc bags for when you're out esp. at the park. in order to avoid shock when using public restrooms, i used that potty for about a year. it's easy to use, and folds when you're done using it. and cleans easy.
let me know if you need me to send you links for some of these things.
don't give up. you're really close.
ps. one of my twins was also speech delayed, but she did understand what i was saying and the process of getting potty trained.
good luck