Alas, most of those lovely markings disappeared with her latest molt, leaving only the anterior-most outlined stripe, a red point above her spinnerets and, of course, her hourglass. I wonder if she is mature now or has another molt to go?

stinks. The remaining markings may fade even more over time, unfortunately.
There are variations that retain their juvenile matkings as adults though, with some good examples on these image pages.
The legs look typical of an adult female, but check the epigynum to verify. It should appear hard and shiny, aka sclerotized. There should be some good ventral views here to compare to.

Thank you for the info! Do you have any idea where I could find such variations of Lateodectus (which keep their colorful patterning into adulthood)?

populations throughout AZ, NM, and TX into Mexico tend to be heavily marked as adults. Rest areas along I 10 in AZ and NM had numerous well marked females.
Here is a great example from TX

Thank you for the ID! =D She is a beauty!