From Face[t]s of First Language Loss, by Sandra G. Kouritzin (Routledge, 1999), pp. 158-159:
Alexandra asserted many times that she was unaffected by the loss of the German language which she had spoken until she was about 9 or 10, that in fact, the loss of German had been extremely beneficial to her.* She insisted that the only loss she felt was the loss of opportunity to speak a second language. She told me these things so many times, and so forcefully, that I stopped believing her.
Born on the prairies, Alexandra was the youngest of six children in a German-speaking household. Her mother was her father’s second wife; her three oldest siblings were half-brothers. When Alexandra was 10 years old, her own mother died and her father couldn’t manage both his family and his farm. Her three oldest brothers, aged 16, 18, and 20, moved out on their own, while the three youngest children became wards of the state and were placed in foster care with families who did not speak or understand German. When her family split up, Alexandra did not maintain contact with her father because she felt betrayed.
Instead, she considered the family that she lived with and grew up with to be her family, and she never even discussed her former family with her foster family. Although she had some desire to maintain contact with her siblings, because she felt no need to see them, and because her foster parents would have found it difficult to accommodate her desire to see her former siblings, she seldom had any contact with them.
She remembers speaking German at her brother’s wedding 4 months after her family broke up, but that is the last recollection she has of being in a German-speaking environment. At this time she doesn’t remember any German words at all; in fact, she says she can’t even count to 10 in German.
*[Author’s note:] I have come to be very suspicious of such claims, which are often used to contradict research directed at heritage language maintenance. Through this project, after close questioning of subjects who initially said similar things, I have come to realize that they do not mean they are glad to have lost the first language, but rather that, if they had to be monolingual, then they are glad to be monolingual in English rather than in some other language.