[apexlocator]

Not a pro at it, but I do have kids and have thousands of photos and footage of them. If you are shooting video during the big moments, who will take the pics? Do yourself a favor and get/borrow a camcorder and stick it on a lightweight tripod or monopod, but dont leave it unattended with kids running around. Just use the one lens, 16-50 and focus on the pics/composition. I put more weight on the photos because its harder to share videos.

Depending on age of the kids, it would help to be able to engage with them to get that natural smile.

Also, if you dont know already, learn to use/bounce flash; your lenses are on the slow side for late afternoon/evening/indoor events.