You've done an awesome job considering you were thrown right into the deep end of the pool with this little girl. Everything you've learned from Kenzie will help the next rescue you do. And once we get settled in and started on a regular work schedule she'll come around just fine. That's a big thing with babies, consistency.
As far as the SWAT, if it becomes too big of a fight to get it on, it may not be worth it right now. If she still has mane and forelock to shake for flies, unless they just overwhelm her, it may be better to wait a bit until it's a bit less sensitive.