The best thing Crystal and Ronald can do for their children is for one or the other to move close enough together to both have stable relationships with them on equal terms. Joint custody and sharing in the care is the best solution. Let everyone come together to raise the children with love and kindness instead of bitterness and jealousy. Forget set visits. Forget who did what in the past. Forget everything except what is important to the children in the moment and for their futures...and do it together instead of isolating anyone who loves them dearly.
When you have a custody battle...yes...one parent wins, but the children lose automatically. The rift caused because of the battle alone is never going away. People need to get over their personal feelings towards the other parent and realize that the children are worth pretending you are friends or however they have to get through it...but there is no room for jealousy, arguing, petty carp, or winner/loser mentality. It isn't a football game or a wrestling match to see who is the better parent as every divorce/custody attorney would like to perpetuate. It is about allowing your children to grow up knowing they not only survived, but thrived through your divorce.