This is a mystery. The diamond "heraldic rose" brooch from the groom is often referred to as being Maud's seven point diamond brooch http://i.pinimg.com/736x/48/2e/b2/482eb29cc3abe555dbd6d8d8eae8b234.jpg (now Princess Astrid/The Ferner family) - but it's no match with the sketch Beth posted.

Wedding gift from Maharaja? 
Queen Maud wore a large diamond sun brooch in the Norwegian Parliament in November 1905 and again to her coronation in June 1906. News reports referred to it as "the diamond sun brooch she received as a wedding gift from the Maharaja of Cooch Behar" (i.e. Nripendra Narayan) in 1896.

The spikes of the coronation brooch looks different from the spikes in the sketch: 



News report regarding the Maharaja gift (for those who read Norwegian):