When a home health aide told Colleen Hertel her elderly mother wasn’t eating, she was surprised.

“She usually had a great appetite,’’ she said. The aide responded that to promote a healthy diet, her mother was being fed yogurt every day.

“She always hated yogurt,’’ Hertel said. “But she was frail and couldn’t tell them.’’

That experience, and others, led Hertel, of Winchester, to write the just-published book, “While I Remember to Tell You, This is Who I Am.’’

The book includes a few narrative stories, but is mostly a workbook and guide for people seeking to “age with dignity and control,’’ Hertel said.

It has a section of questions, some recording people’s preferences. For example, do they like classical music or jazz; mystery novels or fairy tales; watching the Red Sox or soap operas on television?

There also are practical questions, such as do they like a feather or a firm pillow; the bedding tight around their shoulders or loose; if they have a will and where it’s located?

The answers can be filled in by people themselves or by family or friends. The aim is to provide a guide to “who they are, if or when they can no longer tell people,’’ Hertel said.

“It’s about maintaining their inner self. As people age, they don’t stop being who they always were.’’

The book also serves as a conversation starter.

“It can be in people’s rooms or by their bedside so a caregiver could come in and learn the names of their children, and what they like and need.’’

Hertel said the book can be helpful because family members are often spread apart. And some older people don’t have a personal advocate.

“It’s an attempt to let those who care about us and for us to know who we were and in our weakest moments, still are,’’ she said.

Hertel is a retired attorney who concentrated in estate planning and elder-law issues and is on the board of the Winchester Council on Aging.

“But as my book explains, that’s not just who I am,’’ she said. ‘I love gardening, cooking, and writing, and enjoy golf and long walks with dear friends. I took tap dance lessons in my 60s, and adore Stevie Wonder songs.’’

Hertel speaks about her book at 7 p.m. Thursday, Sept. 15, at Book Ends, 559 Main St. Winchester.

WENDY KILLEEN

Wendy Killeen can be reached at wdkilleen@gmail.com.