In Arizona (where I practice), the wishes of the child are only one factor of many that the court must consider in determining child custody matters. In other words, it doesn' t matter how old the child is, it is basically never as simple as "what the child wants." From the information you provided, it sounds like any modification in your orders would have to be addressed in either NM where the plan was created or TX where the child resides (the determination of which is the appropriate court depends on how long the child has resided in TX, as well as several other factors. It does not sound like Arizona would be an appropriate forum. I recommend you speak with an attorney licensed in NM to discuss your specific options.
** This response is provided as general information only and does not constitute legal advice or otherwise establish an attorney client relationship. **