Historical Romance Book Club discussion

I'm trying to remember the title of a historical romance I thought was by Kathleen Woodiwiss. The hero was some kind of a ninja. Adopted into a wealthy family, troubled youth. The heroine was poor. He would sneak into her room at night and watch her sleep, too shy to speak with her. He hid in the rafters when she almost caught him.
Does this ring any bells with anyone? It was one of my favorite historical romances. Probably the 90's

Alinde wrote: "I'm trying to remember the title of a historical romance I thought was by Kathleen Woodiwiss. The hero was some kind of a ninja. Adopted into a wealthy family, troubled youth. The heroine was poor...."

Maybe The Shadow and the Star by Laura Kinsale ?

Darbella wrote: "I have been trying to remember the title of this book for so long. It is a Historical Romance. It (I think is number 3 in a series of sisters/or friends). We met the heroine in the first couple of ..."

This reminded me of Ashes in the Wind. This is not a part of a series.
Heroine is taken in by her cousin's family and she works in a hospital dressed as a boy. The cousin wants to marry the hero, an army doctor for his status and wealth, so there is some kind of courting going on. One day heroine rescues a drunk H from the riverside and brings him home and they have sex. Cousin saw her leaving the room and slips into bed with the sleeping H and they were found that way. Hero doubts it is not the cousin, but consideribg that there is no other woman in the house, he marries her. Cousin dies after a few years and things happen and he gets his HEA.