Thank you, everyone, for your advice, suggestions and concern for Tabs.
We still have to force-feed her but she eats the food willingly. She is alert; just not as active. But there is still no defecation.
Based on the X-Ray, another vet seems to think it may not be hairball but something more complicated which may require surgery.
We will be taking her for a 3rd opinion tomorrow.
Praying for the best.