With those settings, there should be a bright yellow spotlight 3units behind Vampi and about 6.7units up, pointing more or less down at her - I checked this in a blank scene and it all looked okay. Are you sure the back screen is not blocking it all out (sorry, obvious question). I don't know what measurement units you are using.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)