Flutter sleeves shirred dresses

These are my 4th and 5th shirred dresses they are lovely at the front but the stitches at the back doesn't seem to be right. The threads are too loose although my machine tension is set to 9 the highest.  The patchwork fabric is from Dunelm and I'm hoping it will fit my friends just turned 5yr old DD.  2 extremes with these 2 flutter sleeves.  One day I'll get it right.

 Do you know these shirred dresses can be worn as a skirt / maxi skirt too.  Easy and versatile!