I'm an INFJ myself, so I'm comming from my own experience and tendencies to overthink things here...
INFJs, as I'm sure many know, tend to be experts at reading the mood and letting other people's emotions really sink in. Something in our minds just lets us click with the way people respond and react to creatin things and situations. That being said, we are extremely (I pray that this is the correct word) sympathetic towards others and their emotions. This is because we strive to connect with people on a deeper level and have the best interests of others in our minds. But I digress.
The point is, an INFJ would take care to think about your emotions before reacting to them. In other words, even if she doesn't feel the same, it is highly probable that she would not want to stop being close with you for that reason. Love is an emotion to be treasured, not rejected. INFJs have the insight to know that.
As for the "no responce" situation--INFJs are introverted, obviously. Some people more than others, sure. That's why you can never be sure about how she may feel back. Even if you manage to put yourself out there, she may be too scared or cautious to put herself out there to you. Because INFJs are so aware of the treachery that can reside in people's hearts, they can be EXTREMELY cautious about opening up. Even when you think we've opened ourselves up and shown you our deepest, most precious secrets and emotions, we probably haven't. We're just lookingout for ourselves.
BUT!
Once you can get her to respond to you on that intimate level and finally bring down that last wall, there's a lifetime of love, trust, and connection there. It's well worth it.
Hope I helped without confusing you...