NEW YORK (CNN/Money) - The sister who gave you the silent treatment for the stupidest reasons; the brother who always accused you of being the favorite; the wayward sibling who's forever off finding himself (often thanks to a loan from you).

These are now the same people you've got to work with in caring for your ailing parents.

Getting the best care for Mom or Dad is hard enough, whether they live on their own, in your home or in a nursing home. And it's emotionally difficult to accept when once-strong parents grow dependent on their adult children because of age or illness.

But figuring out with your brothers and sisters who should do what and who should pay can compound your stress, bringing out the 13-year-olds in everyone.

Still, it's possible to make the situation less of strain -- emotionally and financially -- if everyone agrees to make common sense and consideration -- rather than sandbox rivalries -- your guiding principles.

First, realize the division of labor will never be entirely equal.

Given the different demands in everyone's lives, not all siblings will be able to contribute the same amount of time, energy or money.

And the truth is, the bulk of caregiving tends to fall on one person -- typically the one who lives closest to the parent geographically or the daughter, who's still the statistical favorite when it comes to eldercare.

That means everyone else will have to make an effort to respect the caregiver's decisions.

The tendency, however, among some siblings who live far away, experts say, is to criticize or make suggestions without really knowing the day-to-day realities of the parent's situation, especially if the parent suffers from dementia.

"The one that's local tends to get dumped on," said certified financial planner Chris Cooper, who runs a geriatric care management firm in Toledo, Ohio.

When the carping becomes excessive, Kay Paggi, who is a geriatric care manager in Texas, will often suggest to the out-of-town sibling, "You do it and show us how."

Even though one child is likely to bear the heaviest burden, that doesn't mean everyone else can't do their part. The key to keeping the peace long-term is to recognize you all can -- and should -- contribute something. "Your contribution, no matter how small, is appreciated and necessary," Cooper said.

When deciding what needs to be done, everyone should play to their strengths. In other words, the brother who flunked math shouldn't manage the books. But the sibling who's an accountant or has the most accountants for friends might offer to do the parent's taxes.

Siblings might also make a special effort to relieve the hands-on caregiver whenever possible.

Do what you can financially. Don't imperil yourself or your children, Paggi said. But make whatever financial contributions to your parent's care that you can afford, if money is needed.

Take care of little repairs. If your parent is living with your brother or sister, offer to pay for and/or oversee repair projects if you can't perform the repairs yourself. From the caregiver's perspective, "It's the little things that can kill you," Paggi said.

Spell the caregiver. Spend the time and money to stay with your parent for a few weeks to give the caregiving sibling a much-needed vacation.

The hands-on caregiver can also do much to prevent family feuds or resentments from building.

Communicate. Address problems with your brothers and sisters when they arise, rather than months or years later. And keep them apprised of your parent's condition so they don't feel left out, Cooper said.

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Keep good financial records. As the on-site sibling, you're likely to incur higher out-of-pocket costs for your parent's care due to last-minute needs or unreimbursed medical expenses. Keep your receipts and record those costs to show just where the money is going. "You need to witness to your siblings what's going on," Cooper said.

Ask for help. A brochure called "How to Get Your Siblings Involved," published by Children of Aging Parents, urges caregivers to let their families know what's needed: "Ask your siblings how they feel they could contribute to the care of your parents. ...Offer suggestions that will ease your burden and still give them a choice. If they decide on the type of support they are able to offer, they are more likely to follow through on their promises." (To order a copy of the brochure, which costs $1, click here.)

Even if all siblings contribute equally to the costs of caring for a parent, the sibling with the most caregiving responsibilities may lose money in terms of lost wages and promotion opportunities.

According to a MetLife Mature Market Institute study, an informal caregiver who steps out of the work force or reduces his or her work hours for four years or more is estimated to lose, on average over a lifetime, $25,494 in Social Security benefits, $67,202 in pension benefits and an $566,433 in wage wealth. (For other caregiving statistics, check the Family Caregiver Alliance.)

There are ways you might try to remedy that imbalance, Cooper said. If the parent bequeaths equal amounts of money to the children, the caregiver's siblings may choose to disclaim a portion of their inheritance in favor of the caregiver.

Or the parent may choose to give some extra money directly to the caregiver while the parent is still alive.

If you and your siblings are having a hard time managing your parent's care, you might consider consulting a geriatric care manager (GCM) who is trained in gerontology, counseling, social work or nursing. A GCM can provide a comprehensive, objective assessment of your parent's needs physically, financially and legally -- and can help you build a plan to address those needs, Cooper said.

GCMs may charge an hourly fee or a flat fee for an assessment. (In the Midwest, rates run between $100 to $150 per hour and about $1,500 to $2,000 for a plan, Cooper said).

RELATED SITES • Family Caregiver Alliance • Children of Aging Parents • National Association of Professional Geriatric Care Managers • Elder Care Online

Keep in mind, a GCM is not a cure-all. The family will still need to manage the manager -- making sure he or she does what's promised in the best interest of your parent. And someone in the family will need to play the heavy if you're not satisfied with the services provided.

Whether or not you use an outside party, it's important that you and your siblings factor in all the costs and benefits -- personal, physical and financial -- to both parent and children before committing to a routine of care.

Otherwise, you risk leaving your family in tatters after your parent dies.

"Nobody has a crystal ball. No matter what you promise or what your parents have requested, look at what's best for everyone involved," Paggi said. "You're going to live with your siblings longer than you are with your parents. You've got do what you can live with because you're going to be living with it."