Oh mom, I'm so sorry. Our son was diagnosed shortly after birth so he was too little to fight too hard, but the screaming and crying was sooooo hard. A couple thoughts: First, if you think she is scared see if you can order an extra nebulizer cup and mask (you should be able to get from local pharmacy same day), and let her "play with it" practice putting it on, play turning the machine on and off when she is in a good mood. Then, maybe try starting up the treatments when she is in a "good tired" (not overtired), fed and if she fights say calmly "this is your medicine. we need to do it" and continue to hold the medicine and cup, and read a book or something she loves while it is going. If she fights to much, turn it off and stop the fun stuff, and say calmly "we'll try it again in a minute. We need to do you medicine." It will likely take an hour of her screaming the first time, but as long as you don't express anger, sadness, frustration, or engage her (begging, playing, or even talking...no matter what she does), she'll should recognize she has to do it and within a week will do it without fuss. (This is the instructions I got from a therapist on oral medications and it worked wonders...but oh, was it hard to do!!!) Sending you a big mommy hug!
PS If she is using albuterol instead of leverbuterol (Xopenex), it might make her jittery...I'd call and see if they'll script Xopenex in case that's part of it.