Nobel Laureate is a bit of an overstatement but she was part of an organization that won the Nobel Prize, similar to how Amnesty International has won it a few times:

The 61-year old climate scientist was part of the U.N. Intergovernmental Panel on Climate Change team that would go on to share a Nobel Peace Prize with former U.S. Vice President Al Gore in 2007. Now, Sheinbaum — who has grandparents who escaped the Holocaust — will hold the most powerful office in the country.

She was a contributing author to the 2007 IPCC report, maybe not a huge deal (there were 100+ authors) but it is reasonably relevant. Here is a chapter that she contributed to (I don't know if there is more than one) and her earlier work is cited.