Jane Foster IS Thor...I mean Thordis...in WHAT IF? "...Jane Foster Had Found the Hammer of Thor?" Conclusion

When Last We Left Thordis, the Goddess of Thunder...

...well, I'll let The Watcher bring the reader up to speed...

Writer Don Glut did a pretty good Stan Lee-style pastiche while penciler Rick Hoberg and inker Dave Hunt gave the story a Silver Age "look".
For the record, What If? later returned to the Thor/Don Blake & Jane Foster relationship with a story continuing from this point...

...resulting in a much more tragic tale...

...with multiple major character deaths!
But, that's a story for another time!

Jane Foster IS Thor...I mean Thordis...in WHAT IF? "...Jane Foster Had Found the Hammer of Thor?" Part 2

We Have Already Seen...
...in an alternate universe, Jane Foster: RN, accompanied Dr Don Blake on his Scandinavian vacation.

When the Stone Men from Saturn (who weren't really from Saturn in any universe, BTW) arrived, she, not he, was the one to find Mjolnir, Thor's hammer!
After driving the aliens off, the heroine now known as Thordis performed the same deeds as the Thor of our universe, including encountering Thor's vengeful half-brother Loki...

To Be Concluded...
...with the most astonishing ending of all time...
TOMORROW!
Misseth it not, True Believer!

As you can see, alternate history is now diverging extensively from the Marvel Universe as Odin helps reintroduce Sif (whom Thor last met when she was a child) to the Thunder God (still trapped in Don Blake's mortal form) before Jane Foster had her memory wiped of Don Blake/Thor, resulting in a romantic triangle that didn't previously exist!
You can read how all that happened HERE!

Jane Foster IS Thor...I mean Thordis...in WHAT IF? "...Jane Foster Had Found the Hammer of Thor?" Part 1

Before Jane Foster became Mighty Thor in Thor: Love and Thunder...
...she had wielded Thor's hammer, Mjolnir in the comics, the first time in what is considered an "imaginary story" (ie: a tale not in official continuity).
But let The Watcher explain...

Verily, the saga continues...
TOMORROW!
Note: In the Silver and Bronze Ages, DC had no problem using the multiverse/parallel world concept regularly, beginning with "Flash of Two Worlds" Flash #123, creating multiple Earths where variations (including the Golden Age versions of characters) lived!

Marvel, OTOH, shied away from the concept like poison, believing everything from the Golden Age Timely days to the 1950s Atlas era to the 1960s Silver and 1970s Bronze Ages could fit in a single universe, with any variations...

...like this being mere temporary glitches in the fabric of the Marvel Universe!
Of course, all that's changed since😱...