Jenny is a victim of "Naive science" - she just wants to make sense of what is happening to her. This has led her on a wild goose chase from indigo child to autism, and a merry go round of unproven and potentially dangerous alternative "cures" for her son's problems. Her altered and upgraded celebrity status is a behaviourally-reinforcing bonus, and has given her life and career new purpose.
To determine cause and effect, everyone has a host of expectations based upon their beliefs about their world and their situation. But "The truth is rarely pure, and never simple" (Oscar Wilde, The importance of being earnest).
She knows what it is she wants to see, so she sees it (this equally applies to "evidence" about toxins as it does to "evidence" Evan started to talk sfter B12, or diflucan, or chelation or whatever).
Her memories of Evan's development/autism seem to be all over the place - the time line is confusing, different events have great significance placed on them, and there are numerous inconsistencies in her story. (Someone should really document all of these for the stopjenny site sometime, but unfortunately it would mean reading all her books and utterances over the last 5 years). Jenny's story keeps changing. Why?
It's because she is suffering memory decay (we all do) and the complex tapestry of memories that was woven during Evan's life have become gradually unstitched. To retrieve the memories, she is (sub?)consciuosly weaving new memory threads, which bear no real resemblance to the ones she lost, but which relate to whatever she wants/needs to remember at that point in time. This is how false memories, which seem very real, can be acquired. Remember, hindsight is 20-20 vision.
So when she says something helped Evan, she thinks it was true because she wished it were true, and her memory of the "evidence" has been reworked. She could probably fool a polygraph convincingly (for what they are worth) yet be totally contradictory - [so was it the B12 injections that helped Evan, no it was the diflucan, no it was the Threelac, no it was the gluten free diet, no it was the chelation, etc - she has claimed each of these at some time to be the cause of his verbal recovery]
As an aside, I see the ubiquitous Jenny/Evan road show have done something good for a change - attending a
stop malaria benefit. Perhaps she's not all bad? One thing I question is whether Jenny has given much thought to Evan's future as a "recovered/cured" autistic. I doubt a succesion of celebrity benefits and being in the spotlight will have a beneficial outcome for him, merely make his adjustments to reality that much harder.