Q: Can my older child have joint custody of my youngest to maintain their current school situation?

A: Based on Minnesota law, your older child cannot be granted joint custody of your youngest child. In Minnesota, siblings cannot obtain custody of minor siblings; instead, they must seek guardianship. Furthermore, third parties generally do not have visitation or custody rights unless they initiate independent legal action specifically for this purpose.

Your concern about maintaining your youngest child's current school enrollment is valid. Minnesota courts consider the child's educational needs and preferences when making custody decisions. When evaluating the best interests of the child, courts must consider "any special medical, mental health, developmental disability, or educational needs that the child may have that may require special parenting arrangements or access to recommended services". The court will also take into account "the reasonable preference of the child" if the child is deemed mature enough to express a reliable preference.

Given your situation, you might instead consider requesting a modification of the existing custody arrangement based on your ex's relocation and your child's educational needs. Minnesota law requires court approval or the other parent's consent before moving a child's residence to another state, and courts apply a "best interests standard" when considering such requests. You could present evidence showing how remaining in the current school would benefit your child's education and emotional well-being. I recommend consulting with a family law attorney to discuss pursuing a custody modification that addresses your specific circumstances.