In Safari, press on the book icon (the bookmark button). Select "Edit." Press and hold the area with the three lines (to the right if this symbol: >). Now you can drag any bookmark around within that folder.
You can also use this method to move any bookmark folders around. Oh, and this works in the Atomic browser, also.
It's not as easy as having the computer sort for you, but it'll do.
Hope this helps.
Marilyn