I learned it from my grandmother and from Gladys's grandkid. Gladys was the last person whose first language was Kiksht, not the last person who speaks it.
> The last fully fluent speaker of Kiksht, Gladys Thompson, died in July 2012
Which is from https://web.archive.org/web/20191010153203/http://www.opb.or...
Maybe there are some sources talking about fully fluent people still being alive? As currently the article gives the impression they were the last person to "fully" speak it.