On one hand, you have the likelyhood she is asuming that at some point in the week you two will have sex. She's coming to stay in your room, she's your girlfriend, she isnt a virgin, and she likes you. It seems like in most, normal, natural cases this would happen.
However, I think you'd benefit from sleeping on the floor for three reasons:
1: She can always ask you to sleep with her, and no harm will have been done, whereas assuming she wants you in the bed might do harm.
2: Building tension is nice. You'll appreciate things more if you dont rush them. You can take the first day just to kiss and then there isnt any pressure to do more.
3: It prooves to her that you arent just interested in her for sex, that you are patient, romantic, and self sacrificing.
Then if there is an issue, like she has worries about sex, dosent feel ready, or worries about what you want her for, she is reassured. If she asks you into the bed, hints as much, or it happens naturally then you'll know where you stand there too.