I'm certain I'm already too late, but what you should do is further increase the amount of electrolytes (ideally at least 90% electrolytes, no more than 10% formula), then increase the percentage of formula slowly with each feeding after they start showing improvement. Keep up the extended tummy rubs (even if she squeaks, chances are this is just from discomfort and pain from pressure in the belly, not you causing any damage to her) and also just perform them whenever you might have spare time; you really need to get their gut flowing again.
Hopefully your little baby pulled through okay.