Hello northdakotagal! I sympathize with you, my son (3 yrs old) has been having tantrums/meltdowns since he was a baby, mostly due to an extremely strong will on top of sensory issues. We're at a stage where my son does not want to share my attention with anyone, so I can't even imagine trying to teach him and others. Do you have the option perhaps to switch her to another teacher? Or maybe you could make a social story for her that helps to define your different roles "When Mommy is at home, I..../When Mommy is the teacher, I..."
What is she like at home?