Would this idea be possible?

Basically, nowadays there are many cases of missing children. My plan is, the children will have a bracelet or a necklace with a gps in it and if the child is like 1-2 meters away from the parent, it will give a signal to the parent. The parent will wear a watch or a bracelet to receive the signal. The signal could be like an alert, vibrating and informing the parent the location of the child too.

I doubt that many children go missing who are properly supervised by their parents.

...R

Nozakai:
My plan is, the children will have a bracelet or a necklace with a gps in it and if the child is like 1-2 meters away from the parent, it will give a signal to the parent. The parent will wear a watch or a bracelet to receive the signal. The signal could be like an alert, vibrating and informing the parent the location of the child too.

There are bracelets\watches that do a similar function, but the GPS would only be capable of rendering to 5-10M or so, and will not operate indoors.

I would suggest that the liability implications of making and then providing such a device to parents would be very significant and expensive to insure against.

How much experience of working with GPSs and Arduino do you have ?

I would suggest you read up on how the[ Smart GPS Kids Watch](http://www.just-mnml.com/products/smart-gps-kids-watch-child-tracker-pendant?variant=28976137338944&utm_medium=cpc&utm_source=google&utm_campaign=Google" shopping&gclid=CjwKCAjwxrzoBRBBEiwAbtX1n5b5LIvPDUfulqI3Jwt3GZ-Aj0KIIWIfnETE4vXrFhiA4iiVpQLv2hoCTmQQAvD_BwE) works