"At this time, the Kindle camera isn’t accessible to children’s profiles — at least the ones under 8."
If you get this error on Kindle Fire using Kids Email, it is a restriction that Amazon put into the Kindle Fire Kids Edition. This is not something that Kids Email will be able to fix, since it's something that Amazon has restricted. We apologize for the inconvenience.
As a work around for Kids Email customers, your child can still take pictures on the camera outside of the app. You can then add the images as an attachment to send pictures.
If you have any questions on how to do this, or need any other information. Feel free to contact us at firstname.lastname@example.org