Al Maha can be booked on line www.al-mahaservices.com and she can even pay for your visa in cash if she books al maha at the airport. Just remember if you pay for the visa you have to pay by card.

As he is 12 he has paid an adult fare so is not an unaccompanied minor, so no Chaparone required. You're a family friend who has escorted him out to make sure he didn't end up in the wrong place and increasing his baggage allowance as he will be staying a while.

If you want you could have a letter from his mother stating she has asked you to accompany him and has given permission for her son to travel in your company, but I don't think it's necessary but may worth as a back up and only used if they are difficult which they usually aren't, but I assume she will meet you at the airport.