Arlene Marshall, right, with her three daughters in 2010. From left, Karon "Bloo" Marine, Cyndi Lyden and Jacki Lyden. (Bill O'Leary)

October last year, during breakfast at home in Wisconsin, I threw a plate of eggs at my sister, Bloo. I wouldn’t say egg-throwing is a habit of mine. Bloo is our mother’s paid caregiver, and I spell her whenever I can, for days, sometimes weeks, and have been doing this for years.

Bloo’s lips formed a perfect “O” as the plate clattered to the wooden floor.

My mother said, “Good Lord! Jacki!”

My sister said, “How childish!”

I found it mightily satisfying.

If caregiving has taught me anything, it has taught me something about my own vulnerability. I say that as a former war reporter in Iraq and a longtime NPR program host who steered broadcasts through 9/11, wars, plane crashes and all the vagaries of our world. It turns out that this job, caregiving for our wonderful, vivacious, fun-loving bipolar mom, is the one that can undo you.

I love both my mother and sister. So why the meltdown?

Our mother started to need daily help in 2003 while I was in Iraq. A colorful and dramatic personality, she became the “Queen of Sheba” when I was 12, in a psychotic break, and “bequeathed” me Mesopotamia. (My younger sisters got Carthage and Thebes.) I wrote a memoir about her inspiring imagination, and the maddening and rewarding struggles for us. But 2003 was a turning point. I remember calling from the Middle East, only to learn that she’d completely lost her memory, down to my name. She’d also lost her ability to walk, talk and retain continence. She had a condition called normal pressure hydrocephalus — which means the cerebrospinal fluid in her brain wasn’t being absorbed adequately. She required immediate brain surgery and a month-long nursing home stay. When she emerged, she called me “Mom.”

Over the years, she has made a comeback on her memory, but the frailty and intermittent weakness associated with aging, the drug regimen prescribed for bipolar mental illness and the ongoing condition with her cerebrospinal fluid means days are up and down. She needs care most of her waking hours.

While I’ve given scores of talks on family mental health, I’ve never really reported from the front lines of daily caregiving. There are almost 66 million Americans caring for an ill or disabled relative, or about a third of all households, according to the National Alliance for Caregiving. We baby boomers are raising a nation of elders.

After Mom’s diagnosis, our lives would never return to our “abnormal” normal. Bloo, who was already a certified nursing-home caregiver, was paid to care for her. Our mother was 72 in 2003; she’s 88 now. In a decade and a half, we’ve had adult day care and a coterie of aides. Then the day care closed, the long-term-care insurance and other money ran out, and we turned to Medicaid — which has been an effective backstop, if a time-consuming one.

With aging, the needs pile up. I’ve spent tens of thousands of dollars on Mom. And, of course, we daughters aren’t getting younger, either. I’m 63, Bloo is 61, and Cyndi is 59. This spring, Bloo had a hip replacement (I covered for two weeks). And last summer, I spent the majority of my time in Wisconsin, backstopping her as our mother pulled through yet another critical hospital stay. That was a 35-day solo stint, a month before the eggs-cident.

The Day of the Eggs, my trigger was pretty simple. I thought I had a free day to deal with a house problem, and my sister dropped on me that she was taking off to spend time with her grandchildren in another state. I told her she hadn’t warned me — she insisted she had — and BLAM!

Later, when I talked to my therapist about it, he said, “That throw was a long time in coming, Jacki!”

Fortunately for me and my sister, I had a life-changing opportunity. I was invited to the Carter Center in Atlanta as one of the beneficiaries of the Rosalynn Carter Fellowships for Mental Health Journalism. I’d met the former first lady decades earlier as a young reporter, when she was campaigning against mental health stigma. Now, meeting her again so many years later, when she extended her hand, looked in my eyes, and invited me to the 30th anniversary of her other organization, the Rosalynn Carter Institute for Caregiving in Georgia, I felt myself go weak. Who has an “Institute for Caregiving"?

My family, that’s who (that’s how it felt, anyway). And in Georgia, our sacrifices and triumphs were being recognized by a formidable woman, global humanitarian and author (and someone even a few years older than my mother). I’m surprised I didn’t fall to my knees and start weeping.

It isn’t that I hadn’t heard the word “caregiver” before, but in my mind it had described Bloo. Now I knew it described me, too. And it was different from when our mother was “only” mentally ill. This caregiving was attendant to aging, and it just got more demanding: financially, physically and emotionally. I would have to make new maps for a path forward to the end.

Bloo joined me at Georgia Southwestern State University for the summit. There were people there of every age, race and background, sharing stories and strategies: military spouses, parents of special-needs kids, Alzheimer’s families. There was even a caregiver with a band: Vince Zangaro, who founded the Alzheimer’s Music Fest. “The words you can no longer speak, but your eyes tell me all I need to know,” he sang, about his dad. Lee Woodruff, wife of ABC correspondent Bob Woodruff, who suffered a brain injury in Iraq, gave the keynote speech.

“It was like a big support group,” Bloo told me, “like going to church, but for a different reason. Just uplifting and things you don’t even talk about, things you might even have to do at home cleaning on your knees, and you’re all on the same page."

They made meals for us and had a party for us, and all we had to do was show up. When former president Jimmy Carter and Rosalynn Carter thanked the “Caregivers of the Year,” honoring these people because they are caregivers, Bloo said that “was about the dearest thing in the world.”

Bloo took away a 10-point booklet of practical tips she calls her “Bible,” many of which involve managing yourself first. I think my favorite is having a script of lighthearted comments to read when it’s not going well (dog and animal stories, in our case) or mood-switcheroos. (Talk about the Green Bay Packers winning! Or Aaron Rodgers’s smile!) We’ve tried writing gratitude notebooks, too, and, frankly, I try not to be so reactive to abrupt demands from home. Our mother understands this is all hard. She says she doesn’t want to be a pain in our behinds. Her job, we laugh, is to “stay above ground.”

But I am also on a path that millions of other Americans are treading. Caregiving arrangements are a Rubik’s Cube for every family. The only antidote to vulnerability is adaptability. And I can’t stress communication highly enough, before the boiling point rises and blows the lid off.

The last thing we caregivers need is more egg on our face. I assure you that when we have eggs now, Bloo no longer needs to duck.

Jacki Lyden, a former NPR correspondent, is the author of the memoir “Daughter of the Queen of Sheba" and a Rosalynn Carter Fellow for Mental Health Journalism. She’s at work on her second mother-daughter memoir.