I really wonder if Maleah had some internal trauma or bleeding from an area, and that is why DV didn't take Maleah to daycare. It would have been obvious to the providers of the daycare. They kept her home, hoping it would clear up. Instead, she died. DV freaked, and tossed her in the ditch.
LEO are probably trying to tie Maleah's death to BB being involved. That may be why they are stalling on charging DV with murder. The issue is "reasonable doubt", if DV and BB flip on each other, both blaming the other, and a jury can't believe either one, with a charge of "Capital Murder"...that isn't something people are not going to be able to convict without a significant amount of evidence.