ITA that Casey got bent out of shape over that comment but I got a completely different take on CA referring to Caylee as her child. CA did say those words but it was in the context of LDB asking about Caylee's verbal skills. CA said Caylee would say a few words or speak in sentences/paragraphs depending on how chatty she was at the moment.
Caylee lived with Cindy her entire life and did much more mothering than Casey ever did. Cindy was trying to make the point that someone else who was not around Caylee as much may not have understood what she was saying. When you're around a toddler a lot, you understand what they are saying but others may hear jibberish (for lack of a better term).
CA also said Caylee was everyone's child. This was (I believe) still in the context of the living/babysitting arrangements. CA/GA babysat Caylee a lot plus she lived in their house and they paid for everything Caylee owned, ate, wore, medical care, etc. So in that context, Caylee was everyone's child in that house because they all raised her. Casey provided nothing in the way of financial support to Caylee and relied heavily on her parents for babysitting well beyond simply living under the same roof.
CA also said Casey was an adult and Caylee was her child during the questioning about Casey/Caylee's whereabouts and the lies she told. CA was trying to get the point across that Casey was an adult. Caylee was her child so even if she lied to Cindy about her whereabouts Casey was her mother and it wasn't up to her to follow every detail of her life.
That's what I got out of the testimony. I didn't see anything sinister with what Cindy said when taken in context with the questioning.
IMO