I think what happened between that time could have led to what happened after 10. For example:
If she were cooking and smoke filled the house, would she open the backdoor to air it out? What about the children eating? Did Haleigh not eat enough for Misty to be satisfied after she stood and cooked for a while, or did Haleigh verbally say she didn't like what she had in front of her? When Haleigh was told to take a bath, is it possible she dumped out Misty's favorite shampoo?
Did Misty really put them to bed physically? Or did she just tell them to go to bed? Maybe they were on her nerves and she told them to go to bed early and they kept getting up?
I think that the events between the time that the family left up until the time she says she went to bed is what will determine what happened. I do think that after 10-3 was when a coverup started and ended..