I would also use a probiotic. This helps the good bugs in their stomachs. I use Probios-it comes in many forms and you can get the one that is easiest for you to use. Plain yogurt is good too-get the kind with the active stuff in it.
Vitamins and electrolytes wouldn't hurt either.
Also, if you can find some ACV (Apple Cider Vinager) with the mother in it. Wal-mart does not sell it. Usually found in health food section of large grocery stores or in health food stores. Give one Tablespoon per gallon of water. This helps keep the bad bugs from growing.
I know all this sounds like a lot but, if she is getting week you need to through everything you can at her. If she was just starting with scours you could try some of it but, as is, I would try it all. You need to support and treat her rapidly.
If you follow my Misc info link you will find info there too. But, I think I have outlined pretty good what you need at this point.