I'm also uncomfortable with disputing someone's account of experiencing abuse, especially considering what has happened historically, combined with the fact that it is unfortunately extremely common.
What I will say though is that experiencing CSA covers a multitude of types of abuse and earlier onset, number and types of abuse and number of perpetrators etc, obviously exacerbates the impact. As far as I know, Jess has talked about being victimised by 1 man, as a teenager. She cannot know what it's like to have been abused as a young child by multiple people and the devastating impact of such violations. Claiming to speak on behalf of all victims is overstepping the mark in a number of ways.
Jess is clearly limited in her understanding as evidenced by her saying that flashbacks are just ordinary memories. If she had ever experienced them she'd know that simply isn't the case. There's also a vast literature to back this up. Similarly, as others have said, the types of intrusive and highly inappropriate questions she asks survivors on her "training courses", are the antithesis of trauma-informed. Stating on her website that she covers the funny aspects of CSA is frankly bleeping offensive.