(1) You certainly can continue it. Can you just say "spin-off"/"continued from" Timescribe's Alice in Giantland (and put a hyperlink to my story, in your story notes)? I'd be honoured to have you develop the older sister idea.

(2) Classic sequels was a lot of short vignettes. They were repetitive vore plots, with very little difference, and were bound by the originals' storylines. I decided I could do so much more if I rewrote them from scratch, got rid of the male giant ogre for example, making widow Mrs Grimble the vore protagonist instead, and also that I could have all the characters from different stories meet and interact, and establish that Brobdingnag, the land at the top of the beanstalk, Wonderland and Oz were all connected.

(3) Re the "occult magic", I wrote the earlier versions in 2009. In 2010, my new SDA church's pastor preached warnings about softcore involvement in the occult. He used Bible texts like "Have nothing to do with anyone who consults the spirits of the dead, or who practices magic or witchcraft or sorcery or divination. The Lord your God is disgusted with those who do these things." Basically, the Bible truth is that all that comes from Satan the Devil in his war against God. I enjoy supernatural miracles in my life and those of othe christians I know, but only by praying to God in relationship with Him, not by messing about with the occult. Many shows (movies, stories, cartoons etc) which I used to love have the flaw that they present eg good witches and bad witches. But it doesn't work like that. Anyone into that stuff is getting it from the Devil, even if they don't know. I've seen it lead people into a madness that eventually brings on suicide. It's happened with 5 people in my own home city of Sydney Australia alone ... that I know of. So I had to remove the magical elements of the good characters in some of the stories.  The most difficult one was Mrs Yoop, the drop dead gorgeous (John R Neill drawn) giantess from The Tin Woodman of Oz (a sequel Baum wrote to his "Wizard of Oz"). She had magical powers too in his book, and used them to permanently turn people into other forms for her own amusement. I thought it sadistic and non-vore related anyway. So I'd have wanted to change her story even BEFORE I heard the sermons about the occult, and make it vore focussed. In Baum's novel, she was separated from her imprisoned husband (who was  vore giant somewhat like the Beanstalk one, and hence locked in a cave cage by Princess Ozma). I prefered to make her the vore character and make her unmarried. Then she got to interact with Peter Pan. (I've probably made a few mistakes in the adaptation along the way, apart from my deliberate changes, but it's hard to keep track of it all).

So hope that answers everything, and again I'm flattered you want to build on the story. I've always wanted to do a spin-off from this, but I was out of new ideas for the 2 years since I finished it. Your spin-off story would be just what we need. The reason for the hyperlink is that it's very hard for readers to find a story by name. If you look at my "Ann O'Malley, Mistress of Scientific Wonders" and its prequel "Captain Miniature and the Red Moll Conundrum" (links below), I put a "to be continued" plus hyperlink to Ann O'Malley in chapter 124 of "Captain Miniature". And I put a "continued from Captain Miniature" plus hyperlink to Capt Miniature in the Chapter 1 notes of Ann O'Malley:

http://www.giantessworld.net/viewstory.php?sid=2520&index=1

http://www.giantessworld.net/viewstory.php?sid=4592&index=1

When spinning off another author's work, I think it's even more helpful to hyperlink it.