Now, she's a normal a girl and if you're watching a scary movie when romance is on the cards, you don't exactly want to be throwing Cannibal Holocaust into the DVD player. Or Fetus (for the record I hope I never see this one). You need to start off light, but you can still show some cool movies she might not even have heard of before. Then again, you're not really going to be watching the movie - but you don't want a boring film either.
Insidious is a good one because it ticks all the boxes. Creepy house, creepy kid and ghosties. It's the classic kinda horror movie couples have been first dating on for decades. It's also the kind of movie that you don't really care about missing and have playing in the background and going back to between make out sessions.
Hopefully she watches this and relates to the main character. This will make her want to spend the night at your house.
She might not have seen it, but she's maybe heard of it and if she's heard of it then one of her friends has seen it probably. Sex, nudity, laughs and the 'fingering' scene is ideal for a date. This is the type of movie that helps the nerves settle, inappropriate jokes to be made and get you a little hot under the collar. Basically, Cabin Fever after all is said and done should get you laid. Eli Roth made it for this purpose.
Just take the risk. Everyone needs to see Pieces.
Horror movies are always the best date movies. Start her off with one of these, seal the deal then watch Sleepless In Seattle.