After looking at more photos (in particular the one DavoST posted below) I think that Queen Maud was wearing at her waist in the 1901 photos from the Opening of the UK Parliament the same brooch which she wore on the centre of her bodice at her coronation.

I know we cannot ignore the evidence Knightship has found from the Norwegian coronation that the brooch was given to Queen Maud by the Maharaja of Cooch Behar, but I am still inclined to think it might be one of the two brooches which her husband gave her as a marriage gift.

Hopefully, at some time the Norwegian royal house will release some information to solve this puzzle.

The brooch I am talking about-- as depicted in a sketch in 1896 of the wedding gifts.