@supercutefuzzyThey have to eat two mermaidic kelps in a row to get rid of the mermaid trait.
I'm watching these threads with interest because, knowing about this issue because my friend's main couple is a mermaid/spellcaster couple, I intentionally waited until my mermaid was pregnant before giving the father the Rite of Ascension. The baby is still a child, but CAS says she's a spellcaster, as does her little motive icon. I'll be watching her carefully when she ages up to teen!
My mermaid half breeds will get stuck with their mermaid form and swim all the time through the floors too. Sometimes their bottom half is invisible. Cant change outfit because only swimwear is a choice