There are sometimes good reasons to leave one of your children a larger portion of your estate than another child as the Wills, Trusts & Estates Prof Blog reminds us in "Some Considerations To Keep In Mind When Making Non-Equal Estate Distributions."
Sometimes a child has greater needs than other children. For example, a disabled child might need the extra share of the estate because he or she is not capable of working. Sometimes a child might have been given large sums of money previously that other children did not receive. And, at other times, a child might have done things that would make a parent want to give that child less.
However, giving a child an unequal portion of an estate can cause problems as the child given a lesser share might seek to challenge the estate. One way to help prevent this is to give the child something and insert a no-contest clause in the estate plan that states if the child challenges the plan, he or she gets nothing.
The far better way is to speak with your children beforehand and let them know your plans. Let them know why you want to give them unequal shares and give them a chance to respond.
Challenges are less likely if your children know your intentions beforehand and know that you had good reasons for making the decisions that you did.
A qualified estate planning attorney can help you make appropriate plans for your unique situation.
Reference: Wills, Trusts & Estates Prof Blog (May 3, 2016) "Some Considerations To Keep In Mind When Making Non-Equal Estate Distributions