You already have a meeting appointment, right? If not, go ahead and send the email and ask for the meeting. If you have a meeting scheduled already, there is probably no need to send the email - save your questions for the meeting and ask then. You may also get a sense at the meeting that you don't need to ask everything once you've heard the explanation - or you may have more questions!
In any event, (jmo), I think I'd go through with the meeting now - the questions you have about the grade/mark relate to this year, not next year. If the school feels there are issues with your dd's performance in class, you can ask how you can help your dd work on them over the summer if it feels like something worth doing.
If they are considering asking her to exit the program, my gut feeling is they would have already notified you this close to the end of the school year. If it is the case, and they don't notify yet, you may at least get a sense of what's up at the meeting.
Any chance to talk things over in person is usually a good idea - I don't see any reason to postpone the meeting. The email, though, might not be necessary if the meeting is already scheduled. There's always the possibility with emails that it will be misinterpreted or intent won't be understood.
Best wishes,
polarbear
