It's possible the tarp string resulted in a blockage of the gastrointestinal tract and is now causing feed/ and water to back up, which would explain the regurgitation you're seeing. Furthermore, the droppings are predominantly watery which is also suggestive a blockage.
At home, options are limited as far as what you can do to clear a blockage; administration of a lubricant, or a laxative such as mineral oil, olive oil, coconut oil, or molasses may help break up any potential blockages and allow normal digestive material migration through the GI tract. Oils can be easily aspirated during administration, so consider offering it in a treat, setting the oil in the fridge to harden, or if available gavage the mixture directly into the crop.
If the absence of the fecal portion in the droppings continues after repeated administration attemts of the lubricants suggested, a veterinarian would be the next best route. Birds that have decreased appetite are often unable to support normothermia due to decreased metabolic heat production in which case supplemental heat would be indicated. Offering electrolytes in her water may also be beneficial.