You don’t need much thread to make these flowers - and gauge is really not necessary. I did those flowers with a 00.60mm hook - I only listed a 00.75mm hook because Ravelry did not had the right size of hook I used, but it really makes no difference.

You can make those flowers in any size you wish! The only necessary skill here is to know how to make a magic ring. Other than that, is a very simple pattern.