DS used to make wonderful creations with lego even adding motors to some of them. All of the lego is here in my attic but I don't think GD has the patience to construct, if it doesn't go right first time it is flung across the room.
We have loads from when our boy's were little and the G ch have been given it to add to the pile so we have a house full of the wonderful little bricks...great under foot with no socks on.
my DH spends ages making up the models all inn the name of helping the kids.
If you check on google there some wonderful little films people have made using lego people and sets ie Theseus and the Minataur. Perhaps you should make a 'granny lego film'. {Not sure if they make Lego zimmers!'