From what I have cobbled together, it sounds as if Debbie tried to put Lisa down for a nap earlier, and either she woke or never went to sleep, and Debbie took her out at 4:30.
I don't think that Lisa was sick, as in dangerously ill. I got the impression that she had a sniffly, cough-y, cold. It didn't sound like the kind of thing that a mom would be watching for fevers, convulsions or diarrhea. But probably enough to make the baby cranky and fussy. So, if she didn't nap earlier, she may have been quite ready to go night-night at 6:30, rather than 7:30-8 as usual.
At 10 months old, my baby didn't need changing during the night. I would never have gone in and woken her to change her because she might have decided that it was playtime.
And personally, I don't think I would have opened her door to check on her, if I had the baby monitor on, as Debbie says she did. Especially if she was restless from a cold - I would have just let her sleep.
I am not saying that because I personally would have done something, that Debbie must have done the same -just pointing out that her actions, as we have heard them so far, do not seem suspicious or neglectful.