The worst part about 2015 is that they had Michael J Fox play his son AND daughter. What's "worst" about this is that they ONLY did it to show off their fancy new camera that they invented to do it.
A George-Lucas-styled "solution to a question no one asked" if I ever saw one.
They should have had the girl who played Jennifer play the daughter. That'd be ridiculous, but it'd be a BTTF kind of ridiculous that would fit. Not the weirdo "cross-dressing ridiculous" that we ended up with.
A joke a friend of mine came up with was that Marty Jr. and the daughter were both born male twins, and the future is more progressive about the transgendered