Belle,
One thing I do is think about these meetings as a "war of attrition." It is a terrible analogy, but. . .
Could your friend watch your other child so that your DH could go with you? Is there another way you could work it so your DH could attend, I find that makes a world of difference.
Think about concrete questions. For example, "does this district have a written (and board approved) policy regarding acceleration. Regarding subject acceleration..., etc." Have you studied your board of ed's stated policies and made sure you know exactly what they are. Are you up on state law re: gifted ed ? All of these can come in v. handy. I found that once I knew our local district policies really well, I could catch the administrators who BS'ed about them all the time (hasn't helped a lot yet, but I believe that knowledge is still useful).
Good luck, keep posting and keep asking questions. Cat