I didn't notice it had flowers...Lol! Oh well.
I wear a size 6.5 and got the small; it's a bit roomy. I think a size 7 - 7.5 foot would fit it perfectly.
 I had the satin ballerina in the past and prefer that for feeling more substantial and feeling less like a padded sock.
Update 5/5/18
These slippers fit better after I washed them and shrunk them in the dryer.