Traveling to other continents and countries can often be very complicated, as the bureaucracy involved can leave many people with their hair on end, but it doesn't always have to be complicated. Normally, you only need the standard documents, but you don't just need the standard documents like an ID card, passport, etc., but it's always a good idea to call the authorities in the country you're visiting and ask if any special documents are required. 

Of course, Mexican companies still need to be careful with COVID safety measures. You'll be required to wear a mask on the plane and at the airport, and you'll need a negative COVID test. You don't need to take the test if you're traveling within the country. However, if you're passing through Mexico to go somewhere else, you still need a negative test. 

However, children can travel without the presence of a responsible adult, but you must select the airline's services for accompanied minors. If you request this service, you should know that the child will receive assistance when requesting the ticket, will be accompanied to the boarding gate, will have the support of flight attendants and pilots, and, at the end, the airline will ensure that the child is handed over to the responsible adult.