Can you try asking her less often maybe? Once an hour or whatever is convenient for you. I'm glad you are going to put your foot down about the underwear. You are a busy woman and you shouldn't have to clean up urine and feces all day long, that's unsanitary for your family and your daycare.
I'm willing to share my toilet training policy with you:
Children will be encouraged and supported to complete self-help activities as independently as possible with regard to dressing, undressing, feeding, and toileting appropriate to their age and level of development.
I will be happy to work with the parent/guardian on toilet training the children once the child is showing signs of being ready to learn, but toilet learning is a gradual process and works best when both the parents and home childcare provider are positive and consistent in their approach. Toilet training must be progressing well at home and the child must be at the point where they know when they need to use the toilet before I will have the time to help them to the bathroom at daycare. Once that point has been reached I will make every effort possible to assist daily to encourage the child to stay dry and use the toilet regularly. Containment in the form of rubber pants over underwear or pullups must be used until one full month without accidents has occurred at daycare to prevent extensive, time consuming cleanups during daycare hours.