Mermaid/Vampire hybrid problem

I personally got a mermaid and a vampire together thinking if they’ll have child it will either be a mermaid or a vampire but I was wrong, it gave me an unplayable hybrid. Things are fine up until the child reaches teenage-hood. When my sim fully developed her vampires form she was also a mermaid but had no hydration bar, only regulars + vampire energy but no vampire upgrade accessible. The CAS is a mess. I can change only the vampire form but I can’t even copy the normal appearance onto the dark form. She changes in mermaid in water alright but quite a hideous one and I can’t access to the mermaid form so yeah don’t try to mix mermaid and vampires unless you want to live with a sims that has 3 different appearances.