Martha was a serial caregiver. She took care of her parents on a sliding scale, first her father while her mother was still in charge, and then barely taking a breath, she took care of her mother who really didn't need much at first.
The tools she used were shuttling, suggesting, silent observation, second guessing, and seeking second opinions on legal and medical matters.
As the live-in offspring she was the vice president of accountability, so by default she was in charge of sibling management.
Chronic illness management requires little besides keeping track of and getting to check ups and refilling medications. As her father accumulated an increasing severity of diagnostic labels given by medical specialists, Martha had to consider what her father said he wanted when he suffered, and what her mother was able to do for him. Martha had to summarize it for her siblings.
Her father's death left scant time to regain footing when her mother started to pass through the here-we-go-again sequence of: what's wrong? what can be done about it? will that medical procedure hurt? Will my mother get better? Familiarity or on-the-job training, call it what you will. The facts are that having done it once doesn't make it any easier. Becoming a caregiver again wasn't a surprise at all.
1 a : awaiting a chance to entrap :treacherous b :harmful but enticing : seductive "insidious drugs"
2 a : having a gradual and cumulative effect :subtle "the insidious pressures of modern life"
b of a disease :developing so gradually as to be well established before becoming apparent