By request, here is a mod that replaces base game Mary Jane with Gwen Stacy, for those who want to have Gwen instead of MJ for whatever reason (I prefer MJ over Gwen myself, but again this was requested).

Note that the blonde hair and outfit come separately, so install both mod files after extracting them both from the zip if you want her to have blonde hair. Otherwise if you just want to play MJ wearing Gwen's clothes, then just install the clothes mod. Do note that the blonde hair is not perfect due to the current inability to remove the main MJ hair underneath, so as a result, a bit of Mary Jane's red hair will be visible from certain angles. Also during the funeral scene Gwen/MJ will wear a black version of the outfit.

Another thing to note is that this does NOT replace any audio files or whatever, so Mary Jane will still be called Mary Jane, not Gwen. 

Finally there may be a few clipping issues with the legs and coat. I tried to fix that as much as I was able, but there was still ultimately a few instances when MJ/Gwen is walking as you play her that I could not completely fix.

Anyways as usual a very big shout-out to the members of the Spider-Man PC Modding Community. Also credit to @Alijah over on the Spider-Man PC Modding Discord who requested this.