In such a situation, and specific advice, and categorical denial of assistance would be undesirable extremes, which can lead to a lot of trouble. In the first case, whatever the choice of girlfriend, she is still someone will lose a husband or lover. This means that she experiences dissatisfaction with what is happening, and the blame will be who? Of course, counselor. If you just refuse to advise anything, it would look like a betrayal. Left in a difficult moment, has escaped... what are you then a friend? Yes, the situation is complicated, but the exit is still there.
The Council not only to give, but even necessary. Importantly, it was vague, blurry maximum. You can walk, that is, around the Bush: "think about it, time will tell, you can not rush with the final decision, how much strong feelings." And the like. It is important not to use words like "patience", "do" or "be not afraid" because this is a specific Council. Instead, you should say, "Usually do not hurry, first of all weighed, and then doing it." This is a harmless information about how often do other people, and a friend if desired, can benefit from their experience. The adviser does not even try to get away from the conversation, to wash their hands or to escape. It gives a person the opportunity to think carefully about, to make their own decisions, not taking responsibility for it.