She probably isn't ready. All kids vary in age as to when they are ready to potty train. Some can be as young as 18 months, while others are almost 4 before they are fully trained. I would recommend taking a step back and seeing if she is exhibiting the signs that she is ready to be potty trained. I know it can be frustrating having 2 in diapers at the same time, but she just may need a little more time before she is able to be potty trained.
If she is ready, the best thing you can do is ditch the pull-ups except for nap or bedtime. Other than that, let her go bare-bottomed or in a cloth pull-up or diaper. Cloth is much less absorbent so they feel that wetness on them and hate it, unlike pull-ups or diapers which pull the fluids away from the skin. Even the "cool alert" and whatnot does not really help train them . It may sound mean, but it has worked for all 5 of my boys (my youngest being 21 months and almost fully trained), my mom's 2 kids, my grandmother's 8.......
Also, watch her closely. Usually it is 15-60 minutes after they eat or drink that they will need to use the bathroom. Try to time her for a day or two so you know her general time frame and start there. For example, if she typically pees 20 minutes after drinking, sit her down at 15 minutes, and wait. the rewards chart helps a lot of children also. Remember to always encourage her, and don't show any disappointment or frustration when it doesn't happen. Kids can pick up on this, and become fearful of accidents, which only slows the process down further.