buckwheatjones, welcome. Although as a skeptic I would note that your mentioning your source is a nuclear engineer is a blatant Appeal to Authority...
Albeit that said authority can do the math, something that is often lacking in most CT'ers...
I would also note that as an owner of a digital camera, unless she had it turned on, she would have had to wait several seconds (if the camera is anything like mine) for the lens guard to clear and the camera come to life.
If I had to make up a timeline (and this is speculation only, mind you, nothing provable here), it would look something like this.
0-1 seconds---Flight 93 crashes. Ground wave transmitted, fireball begins.
1-3 seconds--combination ground wave/shock of seeing crash "almost knocks her off the couch"
3-8 seconds--sees smoke cloud rising, hears 'boom' of crash, momentarity stunned (I mean, how many of us would react immediately in those conditions?)
8-12 seconds--picks up phone to call 911, finds phone dead.
12-15 seconds--grabs camera that is close at hand, turns on as runs for door.
15-19 seconds--exits door, takes position, brings camera up to focus on growing cloud.
20 seconds---takes picture.
Now this is done not knowing the layout of the house or how close things were to her at the time. This may cause the time to vary--my scenario allows, IMHO, that things were very close at hand.
And as Mercutio said earlier, without timepieces we can be lousy judges of how much time has elapsed. I referee soccer, and when I check my stopwatch for elapsed time, I am almost always off by several minutes in how much time has passed--and I have been refereeing a long time...
Again, just a mental exercise, but for your consideration...
Edited to add: and lets give Killtown some time; after all, he is trying to defend this argument of his on multiple boards, given the evidence here, and he can't spend ALL his time with us..