𝐗𝐋𝐕𝐈𝐈𝐈. Following after Imperator's wise decision to store their core data somewhere else that wouldn't be affected by Leviathan's influence, Cartethyia took the decision of replicating her memories and convert them into stars that would join the first ones the created. Unlike the former ones that were more impersonal (which held traces of the past and the future she's come to learn from the stars surrounding Solaris-3, wishes of the people and prayers she holds dear, as well as thoughts that she may want to revisit sometime in the future), these form the essence that is herself. This choice was motivated by her own journey in battling Leviathan and the Dark Tide, by the decisions she made such as splitting herself and her power (both of them leading to an amnesiac echo).
At this point in time, she has come to the understanding that she is not the human she wanted to live as, but an extraordinary being that may be subjected to future perils. Be it the Fractsidus again or bigger dangers that she'll take arms against, she refuses to lose herself and everything she cherishes of herself just as she did back when she split those things from her. In this case, instead of removing them from her so that they wouldn't be tainted by the endless battle she had to face against Leviathan, she copies them. That way, not only she will continue in the possession of all of those experiences, but there will also be somewhere accessible to her where she can regain them if anything were to happen.