Nothing makes sense with them.
I watched the most recent episode, and I was baffled about one thing... The family seemed to be claiming ownership of Tammy.
There were two points that seemed to totally escape them. First of all, if Caleb is marrying her, that means he is taking care of her, right? The family isn't responsible for her any more. No one seems to have made that point to him or Tam Tam. If they're married, they are independent, creating their own family unit. The siblings wouldn't need to worry about taking care of her any more. They're two independent adults on their own. Not to say that this particular couple is prepared for that, but the point should have been raised.
Secondly, it should have been made clear that it works both ways. If he became sick, Tammy would have to work out a way to take care of him. The family can't be expected to take on another land whale on death's door. Tammy is marrying him, not the rest of the family.
Chris's "come to Jesus" talk seems to have been derailed by the simplest of lovey-dovey platitudes. But he didn't mention practical issues at all. There needed to be ground rules set about the couple's independence. Once they're married, someone in the family might offer to help, but it's not an obligation any more. Caleb should have been put on notice that it's all on his shoulders now.
As for Amy, she is as dumb as a stick and since she shat Glenn out, she has been downright unpleasant... whiney, self centered and demanding. She took advantage of Michael earlier in their marriage, telling him what to do and bossing him around, but moving hay bales is different than being a father. She was so eager to be a mother, she didn't consider him. She thought she could just boss him around into changing diapers and getting up for 3 o clock feedings. He isn't the one who wanted the second baby so soon. I think anyone would dump Amy at this point.