I agree, it looks like roundworm.
OK, you dosed her for 2 days with the Safeguard right? Dose at .23ml per pound of weight orally right?
I would go ahead and give for another 3 days in a row (would make a total of 5 days) since she's obviously got quite a worm load.
Worms may be part of the reason her crop is not emptying/is sluggish and that she's not thriving.
I would still finish the sour crop treatment (total of 7 days twice a day) to help with any yeast infection due to slow/sour crop.
If she were mine, I would also give a little white cooked rice with buttermilk or wet mash made with buttermilk daily. This can help sooth the gut and coat irritated intestines.
