Anna. Simple as that. Her baby voice is like nails on a chalk board. I think she's trying to keep up this front and be more like her mother in law and is just failing miserably. Or perhaps the load she must bear as a Duggar is sinking in and this is her way of trying to hide true feelings.
In one episode I recall JB sky diving. And this really annoyed me. So...heaven forbid your children hug their boyfriend/girlfriend with frontal hugs yet, it's completely acceptable to put your life in danger participating in an extreme sport. Backwards line of thinking.