Difference in size...

Brittany💚💛 • I'm 26 years old from New York. I'm currently pregnant with boy/girl twins! 💚💛Due December 2015!
At 27w4d...
Lennox is 2lbs 13 oz. and in the 69th percentile. She still won't show us her beautiful face.
Atticus is 3 lbs 8 oz. and in the 90th percentile. He likes to be center of attention already. We got an amazing photos of him. 
Doctors are concerned about the difference is size so I will have a quick weekly ultrasound to check fluids and growth. Hopefully she catches up. Anyone else have a significant difference in size?