If you're negotiating a settlement/modification, ask the attorney what the issues are and how they may have an effect on you financially. If it's contested ask what grounds are necessary to modify the agreement and whether you have a solid case.
Under the rules governing the conduct of attorneys in New York it may be necessary to remind you that this answer could be considered attorney advertising.
First, find out how often they practice in front of that judge and what percentage of their practice is family law. $3000 is a lot money and a good attorney tries to use their client's money wisely. Do they charge for phone calls and emails? Do they have their paralegals do some of the work to save you money? Can you negotiate a flat fee? Many attorneys accept payments after the retainer is used or will do the work for a flat fee. It's best to try to have a face to face free consultation, but you are out of state. Get a phone consult and see if your personality meshes with the attorney. Read Avvo reviews, too.
First of all if your decree is in Nevada you'll have to hire a Nevada attorney to modify your decree. Idaho would have no jurisdiction to do so.
In your situation, I would first ask the attorney to explain to you each and every factor the courts in Nevda consider when deciding what might be the best interest of the minor child in regards to the schools that are available both in Idaho and in Nevada.
I would want to know how many of " choice of schools" this judge might have handled and if she HS expressed written opinions about what she considers.
Lastly , I would want to know his/her plan on presenting evidence favorable to the judge.