Akuyaku Reijou wa Nightingale wo Mezasu

An unpopular woman in her thirties, our protagonist's only pleasure in life is reading all the web novels she can get her hands on while soaking in the bath. Tragically, she carelessly fell asleep in the bath and drowned, and before she had opened her eyes, she entered a fantasy novel world with a fictional otome game theme. What's more is that she transmigrated as the villainess Leysritt!

All I wanted was to be able to enjoy my second life quietly! But because I saved the prince's life after he was hit by a carriage, the prince's younger brother took interest in me, and now I've become his fiancée?! With my knowledge from being a nurse in my past life, I want to be of help in this world. If I want to avoid a future of ruin… I must aim to be like Nightingale.

(Synopsis: Gourmet Scans)