You know your mother. Do you know the woman?

The part of her life that goes unrecorded

Ask most people about their mother and you get a warm, accurate, oddly narrow account: what she cooked, what she worried about, how she was with the grandchildren. All true. All from after you arrived.

The twenty-odd years before that - the ones in which she was a girl with a temper, a young woman with a job and a plan and a best friend she has not seen since 1968 - belong to somebody your family has never met. And unlike the men in most families, whose lives were narrated through work and service and are at least partly on the record, a great deal of her life happened in places that produced no documents at all.

There is no discharge paper for the year she nursed her own mother. No employment record for the accounts she kept for the family business. No photograph of the afternoon she decided something that changed everything, because nobody thought to take one.

What she is rarely asked

• Her own name. What she was called at school, who she was named for, whether she liked it, and what changed when she stopped being called it.
• Her own mother and grandmother. Two more women, usually with no written record at all, whose lives survive only in what she can still tell you. This is the deepest well on this list.
• The work she did. Paid and unpaid. What she was good at, what she was paid, who she worked with, and what she thought of it.
• Her friendships. The women she was young with. Most mothers have one or two friendships their children could not name, that mattered enormously.
• What she wanted. Not regret - that question closes people down. Ask what she was going to do, and what she was interested in when nobody was depending on her.
• Her own view of the years you remember. You have a child’s account of your childhood. Hers is a different account of the same house.

How it actually goes

Your mother is not asked to write anything, learn anything, or set aside an afternoon. Rosie asks a question aloud, in large type on the screen. She answers by talking. She can stop after one question or carry on for an hour, and she can skip anything she would rather not discuss without giving a reason.

Afterwards, her answers become written chapters - in her words, in her order, with every line hers to change. The recordings stay attached, so the memoir can be heard as well as read.

You can be invited to add photographs and your own memories, and she approves each one before it appears. That is the right way round: it is her book.

The other reason to do this now

Not the grim one. The straightforward one: she is the last person who can answer questions about her mother. Every year that passes takes a little of that second generation with it, and no amount of research recovers what only she was told. Recording your mother is very often the only way anybody will ever record your grandmother.