My daughter tells me my voice wavers when I FaceTime her.

There could be quite a few resons, so please check the following list. Not all of them might apply to your situation, but the all could cause sluggishness in your video conversation.

1. Make sure you are not obstructing the microphone with anything, including your hand. Usually the microphone is on the back side near the back side camera, and on the side near the volume buttons. You can check it's exact location by finding a tiny whole on the ipad body in these locations.

2. Check the wifi signal strength on the status bar. Having less than 3 bars means poor signal. That can really ruin call quality.

3. Try to make a voice only call on facetime. Video needs big data flow rates. If voice calling is good, but video call is bad, you or your talking partner may have a slugish internet connection.

4. If you are using mobile network for your internet/data connection it may become slugish from time to time. Mobile networks always prioritize phone calls over internet/data connection. So if lots of people are making phone calls on your area, yor data connection quality will drop, thus the facetime call using data connection will suffer the consequences by loosing quality.

5.Talking on facetime, or skype using video call is like streaming a video in realtime over internet, and it needs speedy and stable connection. If connection is bad, yor call may become sluggish.

6. Feedback prevention. Try to prevent the sound from your talking partner to get back to the microphone. Try wearing headphones.. Sometimes the sound is turned up so much that it gets back to the microphones, and in order to prevent causing a sound loop (the high piched sound you might heard eventually when people are using microphones on events) your ipad turns down your microphone for a short time trying to protect your ears :)

7. Try not to talk at the same time with your partner. When your partner is talking your microphone might be silenced. Because of what i described at point 6. Wait for your partners to finish their sentence and talk only after that.