Be direct and tell her how you feel. If someone told me that I wasn't giving enough to the relationship, I would immediately apologize and explain myself. As someone who is very aware of politeness and rudeness, I'm sure she's aware if she's crossing the line and being rude, especially to someone she cares about.
When I first started dating my ENFP husband, I felt smothered by his clinginess and constant need for attention. I needed a lot more recharge time, as an introvert, and felt smothered by the constant e-mails, calls, and his constantly being there. We finally talked about it and I said, "you're calling me too much. It doesn't mean that I don't love you, but I need my alone time!"
SJs are very practical. I'm sure you will be able to work out a schedule that works for both of you.
