I agree wholeheartedly, take care of yourself first, but at the same time, do make absolutely certain, even if it's only through another individual, that your friend knows you care and are thinking of her. Don't just assume she knows this. Silence is easily misconstrued as uncaring, especially when one is enduring a troubling time. I trust you don't wish to cause your friend anymore pain than she is already experiencing. At some point, you will want to reconnect with her and it will be far less complicated if you avoid causing any possible hurt or resentment now.