As the inventors of neodymium glass (company name Alexandrit) it's tempting to attribute all pre-war neo production to them but having discounted that option then Riedel would seem to be a good fit, for both pieces. They were a large manufacturer with several factories known to supply blanks to finishing shops and had an excellent reputation for colour experimentation.
The design and style of Christine's piece looks like it could come from the stables of Hoffman or Schlevogt, both of whom had their items made at Desna near Gablonz (Jablonec) which was the location of the main Reidel factory. As inventors of green and yellow-green uranium glass it's no stretch to think that Riedel could have come up with a blue uranium colour, but of course needs researching.
The pale colour of the vase would tend to support dating as pre-war and towards the earlier 1920's when the price of the raw "rare earth" element was at it's highest. As far as I understand it the fashion for Neodymium glass faded quite quickly going into the late 20's and 30's and was revived only much later (c 1970's).