Yes, definitely, but be prepared aswell to protect them from the dust. We think children of 2+ and 4+ can do the Monarch butterflies mountains. We have seen many children in the monarchs mountains. They are not Everests. But aswell they have a certain grade of difficulties: you´ll be climbing at 10 thousand feet. And the niños could easily get tired not of the physical effortment, but of the 45 minutes climbing through out an apparently the same woods. Their attention needs to be cought after a while by something else. And there´s when the possible conflict with the parents come. There are children that preffer to be carried at every moment, and the parents encourage them to walk. For certain couples this conflict ends up in a disenchanment for both: parents and children. Nobody listens to the guide or appreciates the motive of the trip. But aswell, in the other hand, there are children that want to walk even more!
So, if you take them, you take care of them and carry aswell with the consecuencies, which could be kindly memorable.
Children less than age 5 go at 50% usually on tours. But if you need to bring with you a safety chair for you smaller baby, then in that case most tours charge the complete seat or place.
Yes, you can go up there. We have seen very old people up there. Even if you´re in your 90´s you can do it, with the only condition that you´re in good shape. Probably you´ll take more time, but you´ll do it. But if you need to take your time and you believe it´s too much, then you better hire a private tour. In colective tours we have taken people over 80 that walk even better than younger. Once we took a woman who had one lung only: she had lost the other less than one year before: but she made it. Please, see point J.
In our vehicles we accept them only with nappy or diaper. But in the sanctuaries very probably you´ll have to leave them tied by the entrance. No pets allowed in the sanctuaries. If in the vehicles if they mess up the sits, you´ll have to pay a complet car wash with interiors.