So glad you figured it out, once we had a poster who lost her ducklings from them being overheated with heat lamp, very sad. One reason we always ask temps in brooder. they do grow fast, now we need pics of these cuties.
90 is too warm even if they can get out from under it. 85* first week and 5 degrees cooler every week starting on week 2. So when they are 2 weeks old tempos in brooder should be 80* and still able to get out from under heat lamp. Sounds to me like she is too warm, and make sure they can dunk...