Sadie Sink is playing Mary Jane Watson. The estranged sister of Michelle Jones Watson
In the comics, MJ had a bad relationship with her father. With MCU MJ refusing to use the her last name, I can see something similar going down in the MCU resulting in a family split. I can see Peter trying to get to find with MJ after everything what happens in Doomsday to see if she’s okay and coming across her sister. Cue the classic Spider-Man love triangles and family drama.