Marie Curie, I'd just want to talk and maybe get her to be more pushy and assertive, maybe if we had more women as scientists and chemists in general we'd be better off today, it couldn't be worse. It's probably the best idea since it's so close to our society, she is extremely smart so she'd understand the position she is in and that after 2 Nobel prizes she has a lot of vocal power in the world. Maybe, just maybe we'd live in a different world if the good people pushed back against the oppressors, she did lead by example but not many women took her example out of fear , even if they wouldn't be able too, just knowing that THEY COULD would surely push us further, it would have to.
Obviously , I'd tell her about the radiation caused by her use of Radium and Polonium in her experiments which would lead her to avoid dying via anaemia and live more. And also maybe bring one or two modern science/chemistry books to have her "cheat" a bit , wouldn't hurt having an already excellent mind be more excellent would it?
Unfortunately I don't have a time machine.