I potty trained in the child care setting for YEARS. These are some ideas I shared with my moms.
Have you SHOWN her how to go (you go while she is in the room). Let her see the water before and after. You might even put blue food color in the water and show her that it turns GREEN when you pee in it (just hide it so she doesn't try to do it without help).
If she will not sit still on the potty, I recommend that you get a TV tray and a bin of washable toys to play with on the tray (books, wooden puzzles, coloring books). Also, set a timer. Tell her that when the timer goes off she is done sitting. You can add time if she is not relaxing enough to go. Don't put her panties back on her right away so she can SEE the pee come out (it looks different when not blocked by the panties). Just keep her on the tiled floor until she goes.
If you have the doll, you can use tootsie rolls for poops when she is ready for that.
You sound like you are very patient with her. Keep up the good work. :o)
Blessings,
P. <><