Dia de los muertos

Peace upon you my brothers and sisters

I have a question that I need an answer for about the mexican tradition ”Dia de los muertos” (The day of the dead) celebration. Are traditions like these prohibited in islam or not?

Context: I met a mexican girl that wants to convert to islam and needs her questions answered. She wants to have more knowledge about the religion before converting. She is planning to read the Quran aswell