I think 3 of them are definitely childrens books but the 4th book probably isn't. I posted here instead of children's fiction because there is more traffic.
I remember reading all of these books when I was in primary school but can't remember their names.
Book 1: Was set somewhere in Scotland, possibly involved a boggart and a girl named Dody/dodie which was short for Dorothy. I think Dody was involved in a robbery or was kidnapped at some point.
Book 2: featured a scary faceless monk and an evil clown. I think there was timetravel or alternate universes. There was a something to do with keys and clocks.
Book 3: a girl and a boy are asked to test a new type of virtual reality game which it turn out is using there own fears as part of the levels. One of them is scared of all these eyes looking at her and getting closer. One of the children lived on a canal boat.
Book 4: I don't know if this was a children's book, it had a blue cover and seemed to be a collection of stories based on/around Christmas but I only remember the first one. There is a woman about to give birth in the snow and a stranger stops their car to help her. They take her back forgets house so she can have the baby but I can't remember any more.
I would have read all these in the mid to late 90s and the first 3 may have been new out.
I know its a long shot but does anyone have any idea which books I'm talking about?