There were a handful of Twitter trolls who criticized her decision, sure, but they exist for everything. Real humans aren’t criticizing her, and trying to extrapolate a handful of trolls who are probably bots into some sort of sentiment by any group is ridiculous.
If your friend is deterred from standing because of twitter trolls, she has real problems, especially since Hill fully admits that everyone around her including her teammates were very supportive. Kneeling due to peer pressure from teammates, staff, friends and even the Democratic Party is a fake problem.