Not perfect and the first 3D file I've made in 16 years but here something I made for holding your miracle dice for your Sisters of Battle army

Is to small so Increase size of print by 106% for 12mm dice
If you are going to use the 14mm GW Miracle Dice that came with the army box, you need to print at 120%

EDIT: Exchanged the print file with one desined for the 14mm Dice and fixed the file so the words are supported