The Christmas Spirit (a Regency Romance Paranormal‪)‬

Matthew Dunstone, tormented by fevered nightmares in his illness, believes he has conjured up an elf named Francis--and his beautiful sister Trudy. But mischievous Trudy can take human form as the do-gooder Faye Merriwether and the game to ensnare Matthew is on. Problem is, Trudy finds the human world has its rewards, but she can't remain there. Except that it's Christmas-time...  Regency Romance Paranormal by Patricia Wynn; originally published by Fawcett