This has a very Widow-ey look. Probably a Brown Widow, but possibly a subadult Black Widow in poor light.
You got the family, Theridiidae, correct. The Widows are in genus Latrodectus in this family. Your spider is Steatoda nobilis, in the same family. This species was introduced to USA via California. Brown Widows actually aren’t native either. Steatoda species fall into the group of spiders commonly called False Widows. The good news is that they aren’t medically dangerous nor aggressive to humans. They eat insects and other spiders.
Thanks a lot for all of the great info. Now that I know that it isn’t dangerous, I feel even better about gently relocating it to some bushes outside.