We talked about them from day 1. We talked about all the good things and said we were so proud of him for working so hard and doing so well. Then we mentioned the things he didn't do so well in, but only to say that no everything is going to come easy, it's ok to have somethings to work on and we know he will keep working hard.
In our school district, all report cars before 5th grade consisted of a list of all learning objectives (no grades). Students were given a 1, 2 or 3 (3 being the best) or an N or an X. ( An X meant that they hadn't covered that concept, and an N meant that our child demonstrated no knowledge or ability of that subject.) They also had teacher comments.
If you daughter is getting actual letter grades, it's still a good idea to talk to her about it. I doesn't have to be pressure filled. Just let her know that you are so proud of her hard work and that you hope she always loves learning. If there is anything the teacher is concerned about, you can talk to her about it - not to reprimand her, but to encourage her to keep trying, even if it's tough,
Grades are a part of life in education, just like performance evaluations are a part of life in the work place. It's just the way it is.