How far to go?

Tell her you are not ready. Everyone always thinks that it's the girl who's not going to be ready, so she probably doesn't think you're not. You should inform her of how you feel. She would expect you to wait for her to be ready, so she should understand enough to wait for you.

Tell her gently how you are feeling and if she can't respect that maybe you should reconsider your feelings for each other.

Tell her that you are not ready and she will respect you for telling her about how you feel, tell her that you have all the time in the world to get far so why do it when we can just take it one step at a time and enjoy our relationship slowly and then get to the big stuff.

You tell her. It will hurt her feelings at first, but let her know you still want to be with her. If she really likes you she will be patient.

Tell her you are just not ready, she should understand, I mean I would!

Be honest with her. Tell her your not ready for that big of a step in your relationship just yet, and that you hope she respects your decision. Depending on how that goes, you'll see what kind of person she is.

Just tell her that you don't want to go that far yet in your relationship. How long have you been dating? She might have a problem with it, or she may not realize that she's going too far.

if she says no or forces you into it, file a restraining order against her and tell the cops.

Tell her, not just yet. Tell her you want to get to know her better or you are not ready.