Let's put it this way: the first book is doubtful enough, but I could see it being okay for some nine-year olds, if they were perfectly okay with even the scariest bits in e.g. Harry Potter (which I'm not sure is any of them, but then I'm not an expert on nine-year olds). The second is worse, and the third (Mockingjay) really just goes off the deep end in terms of violence, culminating in probably the most depressing 'happy ending' since 1984, except without any of 1984's depth or relevance.
So you could probably get by just reading the first book, and if you have any doubts whatsoever, it's going to be a resounding veto on the series as a whole. Which is overrated in any case. If you want somewhat more age-appropriate fantasy series, has she tried Cornelia Funke's Inkheart series? Those aren't without any violence either, but not remotely in the same category, and if you ask me rather better books.
As for Lovecraft, he's definitely very talented - really enjoyed some of his stories.