Legal Question in Family Law in Nevada

You don't provide a critical piece of information -- where the original existing custody order was entered, and who has moved where since then; that governs which State has jurisdiction to proceed, and therefore what law applies to your question. For an explanation, see the article titled "The Basics of Family Law Jurisdiction," on the Published Works page of our firm web site, at http://www.willicklawgroup.com/published_works.

Your terminology is a bit confusing -- my guess is that the existing order says primary physical to dad, with joint legal to the parents, but if the reality is different, the analysis is different. What you really need is a full consultation with qualified counsel in the proper jurisdiction -- then what you need to do, and how, will be made clear.