"At age 17, she solemnly told me and her mother that she wanted nothing further to do with the "truth"."
And you think the Boys in Brooklyn (er...New York) might be concerned about that...
Regardless of her conclusion after 17 years, a parent would have provided her and every other child in the family, by donating cash to the service counter for field-service and personal study...bi-monthly magazines, book-study books, reference materials, Bibles, Corporate behavior/training manuals disguised as children's religious story books and teen psuedo-guidance books, leaflets, and contribution-box donations on behalf of a child to absolve guilt, for the better part of 17 years.
Perhaps not a huge sum over 17 years, but muliply the printed and non-printed product consumption of a typical, captive JW child, times millions of families and that's a lot of tax-free cash accumulated to invest in real-estate for Jehovah.
Not to worry...the minute the Kingdom Hall door has slammed shut behind her, there'll be another JW kid along to do his/her stint as a consumer statistic for the next 17 years.
Lament the loss?...naaah...Jehovah's "bean-counters" have an architects meeting in the morning.