Suz, another great buy here. I love how you have styled it too.
About the flats: coming form a gal with short muscular legs, absolutely yes. Be careful that the flats in question are low vamp, and you're in business. Play around. I love pencil skirts with flats for myself. It has a little European touch. And a little effortless too. However I do find lots of comfortable skimmers are too round, too bulky for the look. Ballet flats are great, with a little support.
I so share your concern of stumpiness (although I think you shouldn't worry at all, but I know what you mean, same here).
So I will go ahead and give you this little trick for wearing skirts + flats with elegance... I strongly believe garments should adapt to one's body, and not the body to the garment. However sometimes, some styles will bring attention to a part of our body that we find less proportionate, for all kind of reasons, if not just for how we have been raised, for our sense of aesthetics, etc. For me, my legs were the thing. I so wanted to wear skirts, yet hated how my legs looked in them, more specifically: calves which I felt were too bulky, and the inner knee /inner thigh area which also tended to protrude, or sag, or flab in a way that didn't please me. Because I am coquette, and stubborn, after looking for a long time I finally found an exercise which took care of those both areas in one. It was like discovering the Graal. From that day on I didn't need to wear heels when wearing skirts, a big plus in my life.
So pardon my long introduction, due to the fact I so much hesitate to advise an exercise here. But here goes.
This is an exercise from the Callanetics method. Add it to your workout routine.
Find a sturdy chair with legs (What? Some futuristic ones don't have them...).
Sit in front of it, bare footed or with socks.
With your feet, grab each outer side of the chair's front legs.
At approx. 10 cm from the ground.
Lengthen your legs.
Don't lock the knees.
Point feet.
You are sitting on your coxis, pelvis curled.
Now squeeze the legs inward for one full minute, as strongly as you possibly can.
If you don't have a stop watch, count to 100.
Relax.
Repeat 2 more times.
This exercise is shown in this segment, at 13:58
http://www.dailymotion.com/vid.....s-05_sport
Although called "Inner Thigh Squeeze" , it acts on the whole legs, specifically calves. It makes your leg lithe.
I have tried it with the ball, but somehow it doesn't have the same powerful effect on the calves. Maybe because of the softer nature of the ball.