I wouldn't keep moving her about either - hamsters do find it stressful. Herbert - my Syrian - is an awkward hamster (but we love him!) and though for about a month he's been perfectly happy in his Zoozone 2 he's been showing obvious signs of irritation at it the last week! So today I moved him into a different set-up with a cage on top attached via tubes in case he's missing the tubes. But he obviously found the move stressful.
Hopefully he'll settle - and I moved him for his own good - but once he's settled and if he's happy that's where he'll stay. If he really *doesn't* settle in this set-up we'll have to find space for his old tank again which has just been put in the shed! :P
I think Syrian hamsters don't move easily so swapping Treacle about would be upsetting for her.
If you got the tank for free and if you can sell your Imac for a reasonable price you're not really losing money........ as you didn't pay anything for the tank anyway. So in some ways you're gaining? Might work on your mum!
ETA: I can sympathise as Herbert's been waking me up most nights at about 2 or 3am this week gnawing on plastic - and he's not even in our bedroom! It's not a pleasant noise and not easy to sleep through.