Maybe instead of a bookmark you could make Bible covers?? Here is a link to one a member made
http://www.quiltingboard.com/picture...r-t267431.html
Perhaps the member who made it could help you with the dimensions.
Here is a link to another very pretty bible cover another member made:
http://www.quiltingboard.com/picture...r-t274847.html
If you have several gifts in mind and wanted to stick with bookmarks I would suggest making your cross more simply than a LC. Another option is fusible applique.