I agree that early entry would not be good. Given the ability to defer in Scotland, she could end up being two (plus) years younger than her class mates
- and being 17 (even after doing S6) for her entire 1st year at Uni (assuming she goes to Uni
)
Ds, who has a September birthday and is therefore technically slap bang in the middle of the age range, in practice, because of deferrals, was at the young end of the year. 
He still ended up, even though he did the full 13 years of Scottish schooling (ie he did S6
), not able to drink in bars at least during freshers week at Uni as he only turned 18 after lectures started 
He had one (non-deferred) friend who turned 18 in the February of his 1st year at Uni - and another, who had been deferred, who turned 18 in the January of their S6 year.
Not sure why you have discounted the Southside if your dh is working at Glasgow Uni. You mention Garscube, so that presumably means the vet school area. Travel in Glasgow is relatively easy (what we call traffic jams are nothing like the ones you get down south
I've lived and worked in the South East, Bolton, Hull and Leeds
)
Dh used to cycle from Pollokshields to West of Scotland Science Park (and I cycle-commuted to Bath Street/Elderslie Street).
There is also the subway which then links to the Scotrail services at Patrick.
Shawlands Academy is an excellent school regulars on here would be surprised if they didn't see me giving it a plug
and you get a lot more house for your money on the South Side 
....I don't have anything against Bearsden/Milngavie - I was brought up there and went (and did well at
) to Bearsden Primary and Bearsden Academy
albeit a loooong time ago 