I think I found the issue! I looked at the save data and found she requires a PEARL, but what you can find in the beach is a BIG PEARL, so as soon as I edited that on my save (checking for BIGPEARL instead of PEARL), the scene worked!
Oh, then seems that I bruteforced my way into the scene... Thank you for clarifying it!
Edit: I finally found the pearl! It seems that even while using Aura Lapis, the item was hidden entirely, although I do not know if it is only on my end :(
