She's receiving criticism for bitching about Kirstie as if Kirstie is responsible for the tasks, Ammi. At the start of the wall task she randomly states that she now "has a problem with the president of the BB House", which was unnecessary.
I think she's been raised and praised in her bubble of fame to force scripted drama when this really isn't the sort of show where that...works. So she's taken this task as a script from Big Brother, interpreted it as, "right, now I've got to come for Kirstie, because she's Trump" and it's now just a confused and ill-advised attack. Because obviously, viewers know that Kirstie's just confused by the whole task experience and has no say in what has to be done for Big Brother, so in turn the viewers find Natalie's tantrums and "**** Trump!!!!!" sentiments....largely irrelevant when it's literally a game of Lego
Other housemates expressed reservations too but laughed it off for what it was: a dumb task