It depends on what type of counselor she is seeing as to whether or not the counselor would make a diagnosis. If the counselor is has a PhD and is a licensed psychologist than they would have picked up on what her diagnosis is, whether or not they told her. If they just have a masters degree than they may suspect a diagnosis but not be qualified to say that is what she is.

Counselors usually don't tell people what to do. If anything the counselor may have asked questions about your relationship and helped her draw her own conclusion about what would be best right now. Like I said it is probably best that she puts the relationship on hold so that she doesn't stay for the wrong reasons. When she is able to stand on her own then she will also be ready to have healthy relationships. How long this takes is highly variable. If she stayed with you right now the relationship would be one sided, she would be using you for the support you give her and she would be unable to fully give you the support you deserve.