If you follow the instruction in the link provided it will work. Go back and find your error. However before doing so I'd first recommend restarting both machines in Safe Mode , this will clear some caches. Caches sometimes become corrupt and a Safe Mode restart will clear them.
what do you mean your "admin logins on the imac and macbook are different" ?
I want to transfer data from my sister's macbook (aka admin Login is Laura) to my Imac (aka admin Login is Fraser)
of course these are different but I don't understand why I can't view 'Laura's' public folder on Fraser's Imac, whilst I can view 'Fraser's' public folder on my sister's macbook.
I'm starting to wonder if my software has something to do with it (either computer contain different versions of OS X)
Finally got it.
so all those up to my stage, this is basically where my problem was (step 5)
1. Both my comptuer are connected through ethernet (regardless on whether Wi-Fi is 'on' or 'off')
2. I have gone into system preferences and allowed file sharing
3. Macbook (laptop) was connected to Imac (desktop)
4. Macbook connected as: "guest" (this can be seen top of finder window when you have clicked on shared folder)
5. Imac (desktop) failed to connect to macbook (laptop)
All I had to do was:
5. Go on macbook (laptop)
6. Click on ('disconnect' or 'connect as') button top right of finder window (whilst you are on the shared folder of the Imac)
7. Pop up menu. Do not connect as guest. Connect as registered user. To do this: fill in name of Imac (aka first name last name of Imac) then, fill in password for Imac (it is Imac's Apple ID password)
8. Now instead of being logged in as "guest", you are nowed logged in as the *Imac'suser's name* (aka Fraser)
9. I am now fully accessible to all of the Imac's data. Aka instead of seeing "Imac's Shared folder", I can see all files on the Imac free at will.
10. Repeat process for Imac and logg in as registered user for Macbook.
This doesn't require serious 'thought', it is only a process you need to follow. If it doesn't work for you, my advice is to start from scratch (aka. disconnect ethernet cable.. and start again - follow the link below as it is a basic video tutorial if you are unsure what the corrective steps are)