At a literal level, she was to supervise the visit. She allowed the boys to go into the house ahead of her and he was able to shut the door so as to make that impossible. One could argue she was insufficiently on guard because she had become comfortable with this perp and he knew that (of course, I am sure he was willing to kill her if he needed to). She is lucky to be alive. But she did "fail" to supervise the visit. The 911 operator failed to get the right information soon enough to possibly save the boys from smoke inhalation. If we cannot look at all the elements of the situation, we cannot look at how to prevent future ones.
That's why I, and many here, have argued that this perp should never have had visitation at the home because there were too many easy ways that this woman could have been prevented from doing her job, or overpowered and harmed herself - and she was. All the things that went wrong here need to be looked at and changed.
One could argue? One could argue lots of things, even argue just to argue, doesn't make it factual. It was said that they both "failed at their jobs."
Unless someone can show that she was required to either enter first or enter at the same time, that's not evidence that she failed her job.
Many have argued that the perp never should have had visitaion, that has absolutely nothing to do with the SW failing at her job.
The implication is that the SW failed at her job and the boys died, in those minutes that it took her to call 911, the boys lives may have been saved. That's absurd. She "failed" in the same way that even well trained LE goes into situations and get ambushed, totally unexpected resulting in lives lost.
She was calm in her call, and gave him all the pertinent info, it took minutes.