My son is in Portugal on holiday, and can't find any Pokéstops. So, I logged in to his account here to walk to some local ones here and it won't give me any Pokéballs. Can anyone help?
Since cheating has been a huge issue in this game, I would certainly not recommend logging into one account from 2 separate countries simultaneously. The account may be soft banned, see here: Why can't I catch Pokemon in Pokemon Go anymore?