How do I set it up so when my child uses iMessage I can see the messages?

My daughter has an iPod and I have an iPad. We both have separate Apple IDs. How can I see her text message history on my iPad along with my own message history? If I change the Apple ID on my iPad between my ID and my child's, will the iMessage history show up each time I switch IDs on my iPad?

On your iPad, go to Settings > Messages > Send and Receive > Add Another Email and enter her email address. This will generate a confirmation email to your daughter's address, if her email hasn't been used with this Apple ID before. She needs to click the link in that email for you to see her messages.