This was read pre-1994 (most likely pre 1990). I do not know if it was old or new.
It was a novel but most likely under 60,000 words -- so probably read by 7th, 8th or 9th graders. It felt like a quick read.
It is possible that I could be mixing a few different stories today, but...
I specifically recall a world with a brother and a sister (I think) that are pulled into another world (perhaps by a book).
There were talking spiders that the children played yoyo with.
There were wolves that chased them (I believe, seems an a lot like Narnia).
There was a witch that cried tears of acid after a girl placed dandelion handcuffs on her wrists. She was trying to remove the handcuffs.
The children went to a swap meet and traded for some sweets? Maybe it was a sweet meet? The swap meet had a really hippy feel about it (that's my recollection, anyway).
That's about all I remember. I swear it was called "The _____ Queen" or "________ the Queen of Darkness".
I also remember a book drawing them into another world, but maybe that is another book that I'm mixing up with it.