Suspicious App Store purchase emails

Your mother's iPad will take you through the process of creating an Apple ID, but you can also create one on her behalf at Apple's website. Whatever you specify as the country of her mailing address there will determine the Apple Store she becomes associated with.

So the answer to your first question is yes, it is based on the Country/Region you specify when creating a new Apple ID.

The answer to your second question is no, it doesn't matter what you set as the regional localization of your iPad itself. You can change the iPad's localization as often as you like, indeed I do this when moving between the UK and the US. The iPad localization determines things like date and telephone number formatting conventions, spelling dictionaries, and so on.

As an addendum, you can have multiple Apple ID's on a single device. This is kind of annoying to do, but sometimes it's the only way to get an app. In my case, my main Apple ID is linked to the American store, but my London bicycling maps are only available on the British store. So I maintain two different Apple IDs, and when I update my apps I have to type in both passwords and juggle them a bit.

Your mother may not want the hassle of doing that, in which case you are well-advised by @stuffe to keep everything on a single ID.

This is caused by a Mac AppStore Receipt residing somewhere on your system that was issued for different account. Spotlight is generally of no use in finding these, since it can't go deep enough to find them within the places they are. Usually the offending receipt can be located with a simple command, that may have to be adjusted according to your file system structure.

Open Terminal and try:

cd /

then

find . -type f -name "receipt" -exec grep -s -R -n -i "com.ensenasoft" {} \;

• Press Control - C to cancel/stop

if located you will should see something such as:

Binary file Applications/Mahjong Deluxe Free.app/Contents/_MASReceipt/receipt matches

If it failed to locate anything you will need to adjust the path, for example to search a different volume:

cd /Volumes/<Name of Volume>

then try the command again.