The family just got married and they did the cleaning and everything. I thought they were ready to have a baby but I guess they weren't. They were arguing. But they are happy? Why is that?

( I have lite version )

Sometimes they argue, just like real couples. You can make them try again immediately as long as they don't tell you that it's too soon.

Howdy! Can they only have one child in the lite version? My couple's kid just went off to college and it doesn't look like they can have any more kids :P

Yes, the Lite version allows only one child in each generation.