Good news! =D
So, while I was on the way to one of my street puppies, I dropped by at the hospital and asked if I can still visit Su tomorrow or if her condition's gotten worse and I should rather stay away for a few more days. Her doctor said I can still visit her and since her heart has been very stable with the new medicine they're giving her, she's recovering pretty fast. If it stays that way, if her body keeps being that energetic and gradually getting better and ready for the big day, they think it might even be safe to go back on their initial word and allow Su to go home until the day of the transplantation under the conditions, that she takes it easy, keeps taking her medicine twice a day and drops by at the hospital every 3 days for a quick check-up. Of course, if those checks show that something is off again, they'd immediately hospitalize her again, but they said it's worth a try at the very least. =D