She has.
Last xmas and all the ones I've watched her, she's mentioned they do the Xmas "fill a shoebox" for charity and one vlog was centred just around her and her mum shopping for the boxes, ordering essential things like socks, thermals, chocolate etc for them. She's also advocated for Dementia and Alzheimers charities during the marathon and has posted two videos in relation to them leading up to the marathon. I'm not her biggest fan but I dont think she's as heartless as people make her out to be. She might not have done mental health charities but instead charities that mean something personally to her or her family. I don't think anyone should be judged on charity and how much they give and how much they show they give as at the end of the day, by her showing the charity, its giving them some exposure and hopefully her minions might donate bc their queen bee supports it.
I'm sure she's done something with Great Ormand Street but I dont remember tbh and could be wrong about that one.