I bet you look cute in a beret Pat
A little trick that I sometimes use with the kids is to play 'mirror' with them-- asking them to move/hold their head the same way that I move mine, like a mirror, then tilt angle my head different ways and make different expressions. . . it can help if they're stiff (they're thinking about what you're doing rather than getting their picture taken). . . and for a little while, anyway, they seem to think that's fun. . . it helps to get some variety in angles/poses, too. Another trick is to get them settled, tell them to relax that you're just adjusting some camera settings, and talk to them while you 'pretend' to futz with the camera (really you're taking pictures) -- sometimes you can get some really nice relaxed shots this way. . . anyhow, just some things to keep in your back pocket. . . It sounds like you're gonna be ready for them.