I'll second the advice to ask your school - either your dd's teacher or school librarian, and also ask at your public library. Our kids are older now, so I don't have any personal recommendations for that age, but fwiw, when our kids' school started having students do online research in early elementary, guided by the librarian, and were given specific search sites and reference sites and given a lot of guidance about how to know where to look for credible data. We were also given an id/pw that allows any student who is in school in our state to access a state web portal that provides free online access to a bunch of subscription websites that can be useful for students. The librarian at our public library was also really helpful when our kids were researching.
Best wishes,
polarbear
