After pushing and pulling him into his clothes, she spoons him thickened apple juice containing the first of some three dozen pills he must take every day for a myriad of health problems that in recent years have included reflux so severe he vomits blood.
Phifer isn't complaining. She understands this is the life she accepted when she refused long ago to give up her son to some institution. Besides, she loves Billy. When he smiles, she smiles; when he puckers his lips, she laughs.
But Phifer is 74 years old. After years of kneeling over the tub to bathe her son her knees are shot. And hernia surgery last year only underlined what she already knew: her 147-pound son is too heavy for her to move by herself.
"I know I have to take care of him as long as I can," she said. "I wonder who would take over."
Phifer is part of a large and growing population of aging Americans closing in on the end of their ability to care for their children with developmental disabilities.
Experts say government agencies and programs will be overwhelmed by a demand for services as these parents die or simply can't care for their grown children any more.
"It's a nightmare waiting to happen," said Matt Toohey, executive director of Access Services of Northern Illinois, a non-profit organization that assists people with developmental disabilities and their families.
Phifer's household is one of an estimated 707,000 in the United States in which parents 60 and older are caring for children with developmental disabilities. Right behind them doing the same are another 977,000 households in which parents are between the ages of 41 and 59.
At the same time, experts say states around the country are woefully unprepared to help families when they start asking for it. They say the waiting lists for publicly funded services such as residential care facilities — an estimated 58,000 families are on the lists now — don't begin to reflect the need that is out there, or soon will be.
In Illinois, for example, no waiting list is kept. But while there are an estimated 29,000 caregivers over 60 years old, Toohey said there are 500 vacancies in residential care facilities in the entire state.
What makes some of the numbers more troubling is that nobody knows if they're accurate.
"Some people say as many as 40, 50 percent (of these households) we don't even know about," said Tamar Heller, who heads the University of Illinois at Chicago's Department of Disability and Human Development.
The biggest reason is these people have never asked for help.
"They may have backed away from government services because they were afraid if they got the services the child would be taken from them," said Lisa Eden, program manager with the Illinois Department on Aging.
Decades later, "They're still scared the state may come in and take their child away," she said.
But ultimately many will be forced to ask for help, in large part because unlike previous generations, these parents cannot count on outliving their children.
Advances in medicine and technology have seen to that. For example, the life expectancy for someone withhas increased dramatically, from just nine years in the 1920s to 56 years today.
So bleak was the outlook when Luella Jones' daughter, now 52, was born with Down syndrome and heart problems, "We were told she would not live and they encouraged us the leave her in the hospital."
Today, these children live long enough to develop serious health problems of their own. For reasons that aren't entirely understood, people with Down syndrome have higher risk than the general public of developing Alzheimer's disease.
Once parents start asking public agencies for help, it could add up to a staggering amount of money.
"Oftentimes we see an aging mother taking care of a son or daughter on their own Social Security (and) they don't even know their son or daughter are eligible for their own Social Security," said Daniel Scarborough, a project director with The ARC of the United States, a Maryland-based nonprofit organization for the developmental, intellectual and cognitive disabilities.
Supplemental security income becomes available at age 18, noted DiAnn Baxley, director of project training and research at the University of Albany's Center on Intellectual Disabilities.
Nor is it clear where developmentally disabled adults might live when their parents can no longer provide care at home. The facilities available are often understaffed because of low pay, Baxley said.
Among the few places that might be available are nursing homes, though those may not be equipped to meet the needs of these patients, said Heller. Besides, federal law prohibits putting people with developmental disabilities in nursing homes under the age of 60 unless they require skilled nursing care.
There are some efforts around the country to help senior caregivers.
One of those benefiting is Phifer. Her son now rides in a $4,000 wheelchair paid for by Medicaid. Her home is equipped with a device that allows her to lift her son from his bed and place him in his wheelchair or the bathtub with a push of a button - paid for by the state's Department of Human Services.
The same agency hired an aide to help while Phifer recovered from surgery last fall. The aide, Melissa Wright, continues to help. She's paid part-time by the state and contributes more hours in exchange for room and board while attending nursing school.
Still Phifer worries. And she hopes her son dies before she does.
"The only time things are good for these children," said Phifer, "is if they (their parents) are there all the time and supervise everything."
By Don Babwin