The flowers are approximate 3 1/2" across.
I bought the Silhouette files today to make this project; I used 3D peony, 3D Gerbera daisy, 3D large Mums, 3D 5 piece curvy vase. I used eight sheets of 12 x 12 inch patterned paper, lots of glue and a chop stick for rolling petals.
Finished height of vase 5 1/2" tall.
[Photo taken with my iPhone, this is how the flowers and vase looks in real life.]