Legal Question in Wills and Trusts in Maryland

A will can always be contested, so it's hard to guard against that. But in Maryland, children have no statutory claim to the estate (unlike spouses), so leaving children nothing is a perfectly legal and valid thing to do. You may want to at least acknowledge the children and explicitly state that you're leaving them nothing (you probably shouldn't give a reason for this -- that will only give them ammunition to contest). That way they can't claim you've simply forgotten them.

Not on that basis. You are not required to leave anything to your children.