As a reincarnator, Adelaide has a lot of memory related to her past life. It was all so vivid that even those memories she is quite sure to be a blur back when she is still alive can be recalled by her so clearly nowadays that it felt like even though it was her previous memories, her body seems to recognize those memories as not her own and she can only "view" them like some sort of recordings.
But Adelaide is fine with that. Her past life is already a relic of the past that she can access freely just because she was once the main owner of those memories. Using this, Adelaide recalled a few memories related to the thing that she promised her mother of. The medicine that would help a mermaid live like a regular human and be able to return to their regular form as a mermaid anytime they wanted.