I just saw that you are in South Africa, Beautiful country ! I was just there for 2 weeks this past July

Anyway, I understand all you mean, from an owner point of view.
Being a 3rd generation of breeders I can tell you that just the home change is enough change to make a tiny yorkie stressed. Somehow, the continued medication for the full 9 days stabilizes the fecal form. I would avoid giving the sugar, it is only gonna make your problems worse as you mentioned yourself, she may become a diabetic.
I have raised so many tynies ! I have it on my blood lines.
You do what you think it is better of course. But you need to get this puppy stable as fast as you can. Rest, excellent food ( source of stable energy ).
And i would re-peat the meds.
understand different cultures and how they work. Not every single puppy stresses out, but because some do, i hold mine with a deposit until they are ready to go home at 12 weeks or soo... easy transition.
Well, wish you all the best and hopefully we will hear good news soon !
XOXO