Should she truly transform into a simple-minded young dragon, would the sinister dragon still care for her as his [dragon wife]?
With the sinister dragon's penchant for novelty and his quick boredom with the old, if she devolved into a naive young dragon, I suspect his initial thought would be to utilize her as mere bait. After all, having turned into a guileless young dragon, she would be easy to manipulate. In her simplicity, she might even believe that the evil dragon is engaging in some playful game with her.
Excitedly, she would play her part as bait, helping the dragon capture large prey; the evil dragon would feast on the meat, while she contentedly sipped the broth.
The more Lucia pondered the dreadful scenarios that could unfold should she become witless, the more she resisted inheriting the sinister dragon's memories.
She sobbed softly.