Those lil boogers! LOL I know the feeling. I had one baby transverse across the top and the other tucked low on the bottom. She was all nice and head down for a long time then went breech on me. My OB said I had to have her head down to attempt a vaginal birth. I did all kinds of research and learned about chiropractic treatments, shining a light through my tummy at the bottom to "show her the way," playing music down low, having Dad use a paper towel cardboard roll pressed against my tummy to "tell the babies to turn," putting ice packs where there heads were to encourage them to move away from the cold, laying on a slanted board head down etc.
I never really tried any of those things. What I did do was spend lots of time on my hands and knees to give them as much space and leverage to turn. We have a deep bath tub so every night I'd fill it up and get on all fours in the water and sway my tummy back and forth. She was still breech at 34 weeks and I was told there was no way she'd turn. I got scheduled for a c-section. I kept up my bath routine and promised Baby A a car when she's 16 if she'd help mama avoid surgery. Low and behold she turned at 35 weeks even with her sister sitting on top of her. Whooo hooooo. I had an easy vaginal birth. She came out head first and the OB reached in and grabbed Baby B by her feet and delivered her feet first.
I hope you can talk some sense into your girls! 