In cases where the child is approaching the start of kindergarten, or will be transitioning to middle school, junior high, or high school, this can be a closer call. Obviously the quality of the school will matter. Fortunately school statistics are readily available, including standardized test scores. The Minnesota Department of Education provides School Report Cards on their website.
On a related note, it is a useful precaution to close or otherwise terminate additional borrowing authority on any joint credit cards, lines of credit, or other joint debt accounts, when a divorce appears imminent. With respect to joint credit cards and other joint unsecured consumer lines of credit, Minnesota law requires the creditor to close the account upon the written request of either party. 
Your agreement can include all parts of a divorce or focus on only financial or child-based issues. Again, this is up to you. The mediation process is confidential. Aside from agreements reached in writing, everything said in mediation is confidential. Like a psychologist’s office, your mediator cannot be called as a witness to anything said in mediation. This confidentiality lets couples discuss matters more freely than before a judge and lets them move past and resolve issues.
A Motion is a paper asking the Judge or Referee to decide an issue in a case. In a divorce matter, a Motion for Temporary Relief allows you to ask the court to issue a temporary order for child custody, child support, spousal support, and certain property issues. The Temporary Order allows you to get needed financial support while your case is pending in court. The Temporary order will expire when the final divorce decree is signed by the Judge and "entered" by court administration.