How old was Laura Ingalls Wilder when the Little House books were published?

Laura Ingalls Wilder began writing the Pioneer Girl manuscript, the predecessor to the Little House books, in 1929-1930, starting when she was about 62 years old.

Laura was 65 years old when Little House in the Big Woods was published in 1932.  She turned 76 the year the final book in the series, These Happy Golden Years, was published.

She had been published in journals and magazines prior to publication of the Little House books, however, with her first column appearing in the Missouri Ruralist in 1911, when Laura was in her mid-forties.