The real tourist areas of Mexico are still great and convenient destinations for families. I recently spent time in Cancun and Puerto Vallarta with my family...including small children. We had a great time and felt totally safe. You just need a good travel agent to advise you on the best places to visit and stay!
Playa del Carmen is about an hour south of the Cancun airport with a number of really deluxe properties that would please even the most sophisticated travelers. There’s no need to leave the grounds of the resorts unless you just want to explore. 
We stayed in a condo complex on the beautiful beach right in downtown Playa del Carmen. There was a great restaurant attached to the property, so we ate most meals there. Since my 3-year-old grandson was with us, we had breakfast and snacks in our condo. Every morning we headed to Starbucks to start the day and then wandered around the charming little town. Very relaxing. We’d go
again tomorrow!
Our stay in Puerto Vallarta at the Marriott was disappointing in only one way: It was unseasonably cold the first week in February, so not a lot of beach or pool time. But given our winter in North Carolina, a high of 70 degrees with a little wind still was a great break! Puerto Vallarta is on the Pacific with mountains coming right down to the coast. My 2-year-old granddaughter had a great time with the vendors who had scheduled times on the beach to sell their handmade jewelry, scarves, etc. Of course, she came home with a bracelet with her name woven into it and one for her cousin too! The vendors were friendly but not pushy at all.
Emily adds her two cents!...
The first picture is of Tucker flying the plane to Mexico. Before you get too concerned it was all prior to take off. Just when you thought all the friendly airline employees had been fired or were just too worn out to be nice any more, we encountered the nicest two USAir pilots ever. When Tucker peered in the cockpit during boarding they invited him to come in and make himself comfortable behind the wheel of the plane. It was a memorable way to start the trip!
The second one is of Tucker and Jason enjoying the live music that serenaded us every afternoon from the ocean front infinity pool. We stayed at El Faro, a relatively new condo development right on the beach. They had a full service restaurant (Wicky’s- we had shrimp tacos for lunch almost every day!), nice guys who would deliver margaritas to you poolside if you didn’t want the 20 steps back to your condo. We highly recommend it for families and Aladdin can book a unit there for you. We can also recommend which ones not to book….
I am adding another shot of Tucker leaving our ground floor condo, just steps from the beach and pool. Being just "steps" away is a good thing!