It's been said a lot on here that Disney Land Paris was the start of her downfall but I actually think it was people finding out about the house being shared ownership. I remember being on the Mumsnet threads at the time and that was where I first read about it when she started talking about moving house. Someone (local I think?) spilled the beans that the house was in fact shared ownership with the council and a quick Google brought the details up. People were genuinely shocked to find that out because there had been no indication that was the case, especially since they'd done the extension / conversion and new kitchen etc. She had been portraying this aspirational lifestyle with a lovely home and when it came to light that they didn't own it fully, it was the first indication that all wasn't as it seemed.
Viewers started to realize that maybe she wasn't being honest and truthful about the lifestyle that they were presenting. If she's lied (by omission) for years about living in a shared ownership house, what else had she been lying about? She essentially kept that piece of information from her viewers, and that's fine, she never had to give away every single part of their lives. But let's not forget she put a birth video on Youtube so we're talking about someone who's obviously comfortable sharing intimate parts of their life. But yet, in all the years of being online, it never once came up that they lived in a shared ownership house. Funny that. People didn't like the fact that they'd been deceived and they went on high alert for other instances of her deceiving and misleading. When Disney Land Paris happened, the floodgates opened and her reputation as someone who couldn't be trusted was cemented.
In light of the recent events, it's just another example of how putting yourself in the public eye and opening your life up to the scrutiny that comes with that will eventually come back to bite you. But she'll never make the connection between what she does, or doesn't, put out there and the consequences it brings her.