A historical romance that's been bugging me for years. Please help me solve the mystery.

Hi, I am new to this site and I am trying to find a book I read years ago. I do not remember the name of the book, the author or the characters name. The story is set in the Elizabethan era (at the beginning of Elizabeth I reigns). The heroine has a physical deformity of one leg. She lives (or owns but not sure) a house where she has tenant (although I don't think they pay rent as they are more her friends than tenants). The tenants are actors or writers and are kind of flighty. Her family sends her money because they don't want her around as they don't consider her beautiful enough to make and advantageous marriage and she has a limp, so they are focusing all of their attention on her younger, beautiful but completely dumb cousin. An arranged marriage was agreed upon years ago between her family and the family of an Earl and on the night of her cousins engagement party the heroine went there to speak with her father and aunt to ask for more money but the aunt told her to leave and as she was she met the future groom who found her beautiful and a lot more interesting and intelligent than her cousin. The secondary plot involves a series of murders been committed where the victims had their body drained of blood. The heroine initially thought she was committing the murders because she experienced blackouts and woke up covered in blood. The earl convinced her that she was not the murderer and they set out together to hunt the killer. I think there was also a prediction made that involved someone dying during a lunar eclipse.

Still trying to find this book