Dear Mrs. Riches,
My brother "Hank" and I have been estranged for quite some time, and money is at the root of it all. As the oldest son, Hank got the bulk of our parents' estate after their passing, despite the fact that my sister and I were the ones who took care of our parents when they were aging and in poor health.

While Hank and I stopped speaking after the bequest, I thought I had made my own kind of peace with the situation. That is, until recently, when two things happened: 1) Hank has reportedly taken up with a young woman whom the family thinks is after his fortune, and 2) at the same time, he has failed to step in to help my sister with big medical bills resulting from a surgery that's left her unable to care for herself. My parents, old-fashioned as they were, surely expected that, as the oldest son, Hank would take on the responsibilities as well as the perks. But here I am caring for my sister as best I can on a shoestring and there he is, living large, without regard to anyone in the family. I feel so infuriated I don't know what to do. Do you have any words of advice?
-- Fuming Mad

Dear Fuming Mad,
You don't need me to tell you that money can make a mess of family relationships, especially the kind that were strained already. Compound the situation with the deaths of loved ones, sibling rivalry, illness, feelings of powerlessness, and resentment, and you have a surefire recipe for ongoing discord.

It would be great if there were an emergency antidote to this kind of emotional poison -- something that worked immediately and without nasty side effects -- but sadly, the best allies are typically time and forgiveness. While Hank's behavior doesn't seem to be begging for the benefit of the doubt, the tricky thing about forgiveness is that it's much more about the giver than the receiver. You'll work to forgive, in other words, because it's part of your own healing, whether or not Hank ever sees the error of his ways.

That has a very dissatisfying ring to it for most folks (after all, shouldn't the fellow in the wrong suffer just a wee bit more?) but I would argue that this is where you have the opportunity to exert the most personal power. Many of the circumstances you've described are outside of your control; here is your opportunity to make a stand against Hank and say, "I will not let your bad behavior ruin my life." It's certainly not easy or immediate; the path from rage to forgiveness is long, with steps both forward and back along the way.

Although you don't say it, part of your healing may also include needing to forgive your parents. While you may understand their reasoning behind leaving the family fortunes to Hank, it doesn't mean that it doesn't hurt. You sound as if you were a devoted daughter who demonstrated her love and loyalty through action, so it must sting to have Hank's maleness be the determining factor in the inheritance. Yours is a cautionary tale for all those folks out there who plan to leave their children differing amounts in a will: Do think long and carefully about this. While the motivations behind the inequity can be numerous (old-fashioned ideas, an attempt to punish or reward, or as a way to acknowledge that some of your children may need the money less), the result is often the same: The child (adult or not) to whom less is left feels hurt, neglected, and often, less loved.

So please, readers, do your families a favor and give very careful thought to your estate planning. Otherwise, as in the case of poor Fuming Mad, you can leave a festering wound and damage relationships to a degree that simply cannot be fixed.

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Fool contributor Elizabeth Brokamp is a licensed professional counselor who regularly talks money with her honey, Robert Brokamp, editor of The Motley Fool's Rule Your Retirement newsletter. To get your money and relationship questions answered, send her an email .