I usually hate all these types of threads, 'catching out' personalities - whether true or not, it seems witch-hunty ... BUT in the case of Jack, her inconsistences have been rife, and she has variously portrayed herself in a myriad of different roles and situations. There is a huge attention-seeking aspect to what she does - assuming every kind of illness and crisis that can possibly occur and then making it her 'thing'.
I feel fairly knowledgeable about Jack, having read her Poverty Hurts blog at a critical time in my own life, when my abusive marriage was at its worst, and when I was in serious financial difficulty thanks to said abusive marriage. I found it profoundly moving and wrote to her, she wrote back a few times and we would exchange tweets etc (all back in the days when she wasn't famous like now and did things like this). I read everything she wrote or was in, bought her books, followed her career, and while I can't speak about her finances any more than anyone else can, there is just no way that all the claims she makes about her living situation and state of her finances can be true.
I can readily believe she (and many authors) make very little, overall, but not to the extent that she describes the bone-grinding poverty in her latest blog - the melting of soap, no lightbulbs, pawning all her possessions. She does have the resources and contacts to get a regular job / gigs that would enable her to have a reasonable income, certainly one that she and her child could live on, perhaps frugally, perhaps without any huge spare money but definitely manageably.
One of Jack's great strengths is her writing ability (very similar to another person similarly being less than truthful, Liz Fraser) and she is engaging and believable.
Over the years, many many people, who could ill-afford it, have donated to her enterprises, and this is the part that is quite sickening, really.
There are clearly MH difficulties of one kind or another there but at the same time it seems often deeply cynical, how she chooses to write and portray herself, changing facts as it suits her latest narrative.