They dont recommend against it. Its just the lack of evidence and a strong benefit/risk analysis that prevents them from recommending it in patients under 12 at this point.
Thank you for your reply! She was given it starting on Saturday and seemed to do fine. I did end up getting through to someone and they said it was fine to give because she had been monitored while on it. I can't find any info as to why it's not recommended for children under 12 but they seem to find it appropriate, so I'm going to assume it should be?