Recommend you follow the advice to take the AVE to Seville from Madrid. The train experience is great and ez. Show up at the station 30 minutes early, go through security and then you will board the train (completely in control of your luggage). Buy your tickets on line NOW at RENFE site. Using the RENFE site will be your biggest challenge, but it offers money saving opportunities. On Tripadvisor is a great report on how best to use RENFE step by step. Buy coach class tickets, the on board experience includes great seats, audio and video opportunities with free headset, a food car (not that great) and huge windows to watch the countryside breeze by. NOTE: you must commit to a specific time slot when purchasing the tickets and the tickets are only good for this train time (standard for everyone's tickets), so plan carefully. The AVE should be a great experience for a ten year old. The drive form Madrid to Seville is BORING!
Spend the time you desire in Seville and then you have the option of renting a car or taking trains/buses to your tour of Andalucia. If you desire to drive I recommend checking out the transportation page on RS for other travelers experiences. We utilized Autoeurope (a consolidator) and ended up picking up the car from Hertz. You should goto AAA and obtain an International Drivers Permit for $20. Take your passport and drivers license with you. The IDP is required by law in Spain and if you do not have it the fines are over 200 Euros to be paid on the spot. Don't take the risk. With three people and luggage I would not rent a compact, but an intermediate hatchback should suffice. Use caution with leaving anything of value in the vehicle. We found parking just outside the tourist zones to be ez and then take a walk into the tourist zone.
Driving in Spain is ez and the highways are great. Do pick up a GPS as they are quite helpful, the one we received from Hertz even gave warnings for known video speed traps. There is really no need to take a toll road.
From Seville to Ronda drive time is under two hours. Great bull ring and huge gorge which should hold a ten year olds attention.
From Seville to Granada drive time is four hours. DO NOT ATTEMPT to drive in old town Granada. You must book online your tickets for Alhambra. Read up on how to do this and carefully select the time desired you want to visit. The tickets are time stamped. Alhambra is great and should hold the attention of a ten year old, especially if you emphasize this is a location where princesses, princes, knights and moors walked the grounds. Get their imagination going and they will do the rest.
From Ronda to Granada is three hours.
Consider driving from Granada to Malaga via the coastal route. Under a three hour trip. Recommend dropping the car at the Malaga train station and taking the AVE from there back to Madrid. RS pans Malaga, we enjoyed it due to there being fewer tourist. There is a nice fort offering wonderful views of the Med, a harbor and a really nice old downtown area filled with nice shops and good restaurants.
TIP: use Google Earth street view to identify specific routes with attention to entrance/exits to highways and entering towns. I found it helps to find a building to use as a visual marker to provide reassurance I am at the right place. Takes away from of the anxiety of the travel.
Even with 11 days (hoping this does not include travel days to and from USA) visiting Madrid, Seville, Ronda, Granada and Malaga is ambitious (unless you are into saying you "were there" but not taking the time to create great memories). Finally, take the 10 year old into a Tapas bar and have them pick out tapas. It is a way to engage them and potentially expand their food universe!