Most Helpful Guy
She's not good at dealing with relationship pressure, and, whether you know it or not, you put her under a lot of pressure by asking for a definition of what you were.
So she got defensive,
and started talking about boundaries and the like.. I think you may have put the wrong foot forward, for sure.
Back off for a while and see how she responds. Most likely she wasn't serious about this idea of setting boundaries, she just was trying to ward off any more conversation about who was not opening up, who wasn't serious, and so on.
Most of all,she is going to blame you whenever you start discussing problems you are having!