Casey seemed to surround herself mainly with guys, not young women her own age. Granted she was friends with Amy but other than Amy (who had only known Casey for a few months), who did we see testify that was a female friend? And for that matter, how often did she have Caylee with her around Amy? Mallory's testimony was just bizarre. One one hand she says she and Casey were not all that close but then says she had an amazing bond with Caylee. How on earth would she be able to have that opinion if she and Casey were not that close.
Women are, in my opinion, more likely to notice and gauge whether another woman is a good mother. Yes, Tony and his roommates are now saying that they wondered where Caylee was all that time during the 31 days but guys that age, particularly ones that do not have children of their own, are not going to question it all that much other than think of it, question, then shrug it off. Women, on the other hand, are most likely going to delve a little more deeper and not too long begin to think this situation is just not normal and something is very odd here. It's too bad Maria wasn't there longer or didn't live there. I think if she had, the lid would have been blown off of this situation much sooner that it was. She noticed just the weekend she was there things were "off" a bit.
Nate did say on the Sean Hannity radio show this week that he said to Casey one time during this period "are you you have a daughter? I'm beginning to think that you don't really have one" or something to that effect. I can't remember his exact words. He said she just laughed it off, kept on cooking and said oh she's at yada yada yada (my yada not his - he said where Casey said she was) with the nanny. He said that he often thought there really wasn't a nanny cause he knows how expensive it would be for Caylee to have been with a nanny as much as Casey said she was. He said he usually just thought she was really with Casey's mom and Casey was saying nanny to look cool or something. He said thinking back on that conversation now he thinks it is just down right eery that she could have that kind of joking/laughing response to his comment now knowing what he knows (i.e. that Caylee was already dead and in that swamp on Suburban). It was a very interesting interview that he had with Sean Hannity. He was on the phone with him for about 30 minutes.
IMO
ETA - I forgot to mention that Nate also said he wanted to dispel the rumors out there that Tony did not like Caylee being around and had told Casey he did not want kids. He said what had actually been said is that their apartment was a "college guys" apartment and that they all felt that environment was not necessarily a good place for a toddler to be around but that they all, including Tony, really liked Caylee and enjoyed her being around when she was there. Yes, he said they had all said this to Casey.
So, in my mind, it's very clear why Caylee all the sudden became a problem for Casey. She was infatuated with Tony and his lifestyle. Ricardo didn't seem to have a problem with sleeping in the same bed with Casey and Caylee. Tony obviously did.