Can Mary Jane sustain her own title?

[Confuzzled Mutie]

Rogue, Storm and Emma had limites series and all failed.
Marvel always tried with Black Widow, but sales never get together.
The only exception of your examples is She Hulk.
With The Wasp, Marvel never tried.

Mini series and limited series hardly ever work, no matter who the title character is. So that shouldn't count. As for Black Widow, Marvel always made half-assed attempts for her. After the success of The Avengers movie, it was the perfect time to release a BW solo. But instead, they brought out a Hawkeye solo saying it featured the "breakout star of the Avengers". Yeah.. right. Ironically, Hawkeye now co-stars Clint with Kate Bishop!

And not giving She-Hulk and Wasp their own solos or at least their own buddy superheroine comic is a travesty on Marvel's part.

Ms Marvel can’t support her own book because she’s awful.

True, she was most interesting as a ghoulie in Rogue's head.

[Mister Mets]

I think she could be a central character in a book centered around the civilians of the Marvel U. But outside of reviving SM Loves MJ, I don't think she can hold a book by herself. Maybe a special.

That could work if there's a reason for her to interact with a lot of civilians. Perhaps she gets a talk show, or something.

This would have been the opposite of a solo title, but pre-One More Day, it would also have been possible to have a monthly in which Mary Jane was as prominent as Spider-Man.

That approach would have distinguished the book (Web of Spider-Man would be a fitting title) from the other Spider-Man monthlies. This could have been a title that focused on the people she interacted with, rather than Peter's supporting cast.

An early arc could have been more about her reaction when one of Spider-Man's enemies decides to go after her.

A risk is that it might have become a comic book equivalent of Raimi's Spider-Man movies, with Mary Jane consistently kidnapped by supervillains. It could be done in the future, if Peter and MJ reconcile.

Ms Marvel can�t support her own book because she�s awful.

I sort of expect that Storm COULD support her own book if Marvel actually tried it.

MJ�s last series ran for longer than a lot of attempts at new comics.

Ms Marvel's book went for about fifty issues under Brian Reed. That's respectable.