Unfortunately, more times than not, siblings do not share equal responsibility for caregiving for our parents with dementias and Alzheimer’s Disease. Sometimes it’s a simple matter of physical distance: they want to help, but they are too far away.
However, that is generally not the reason.
Parent-child relationships are complicated from the get-go and each child makes a conscious decision whether to maintain a close relationship or not with his or her parents as an adult (usually as soon as he or she leaves home). These are heart decisions.
For siblings, much of whatever the tenor of their relationships were growing up extends into their relationships as adults.
However, one of the complicating factors is real and imagined grudges and resentments (known or unknown) by siblings, often from perceived wrongs that occurred all along the way of their lives, that are nurtured and grow into full-blown anger and disconnection from each other and from the family.
This happens disproportionately more often than it doesn’t, but if caregivers find themselves in the rare position of having supportive and engaged and grateful siblings, then they should count their blessings.
Going Gentle Into That Good Night 
My two brothers live interstate so most of the support role falls to me.
I am not my parents’ carer; my mother (90) is still driving, cooking, shopping, gardening and has cared for my dad (also 90) for the past 2 years.
He has just been admitted to permanent nursing care, and his needs are being met. It is mum who I am now supporting with daily visits and chores, and emotionally.
While several thousand kms away, my brothers are incredibly supportive and phone mum and/or me regularly. My eldest brother came to stay with mum for 2 weeks while dad was in hospital. My other brother will be visiting soon, before his work takes him overseas for 2 years.
Their families are also caring and supportive. One nephew lives nearby to me and mum, which is a bonus.
We are all in regular contact; my brothers are the first to know when it’s time to phone mum, at those times when she needs a lot of reassuring attention.
And I can’t overlook the support of my husband. Although he has health issues (soon to have open heart surgery), he is my rock and anchor.
I am indeed lucky to have such a wonderful family. They regularly feature in my daily list of blessing.
You are blessed, because your situation with your family is not typical in caregiving within families. I’m very happy that you have so much loving support surrounding you and that your mom and dad have you kids all in their corner.