Edinburgh is probably the best place since it has the mix of shopping, museums, the attractions etc although it's quite a drive from Perth, are you OK with city driving? It will be quite expensive as well to park, what I normally do is park at ingliston Market near Edinburgh Airport an get the tram into Edinburgh, you can get a all day ticket an it also stops off at a small shopping centre on the way into Edinburgh
There's also St Andrews an Dundee as well, it's been a while since I was at both, St Andrews has lovely sites an weather permitting could be nice to walk around, Dundee has some museums as well am sure an also could be lovely to walk around, there's also the stirling area which has their town with the castle an monument an the shopping centre which is ok, most shopping centres here have been hit hard with big names going unfortunately, an there's the safara Park as well just at Blair drummand
I'd also look up whats going to be open when you come, scotlands half term may not be the same dates as England an Wales, we don't share the same dates with a few holidays like the summer holidays as we break off much earlier an go back before England an Wales and February will be classed as being off peak which means many things won't be open as they are seasonal, so if you are coming when schools are on here then some things may be closed
Also bring a ton of warm things, further up you go the colder it will be, you could also be looking at it being mostly raining an windy as well, not sure where you are from but we Scots aren't kidding when we say the weather gets rough here, you might even have snow in February as well