I have been getting lots of questions about twin birth lately, including a few comments in some of my past posts... so, let's look at the normalcy of twin birth:
This birth is great because it shows that twins can be carried to true maturity, not 'medical' maturity (37 weeks).
Here is a great one of a water birth of twins were the sac is intact for baby B.
Here is a lovely home birth of twins, a VBAC (HBAC), Baby B born 2 hours after Baby A. Baby B is posterior.
Hellena Post has an amazing birth story of her twins, where her twins don't come immediately one after the other (and safely)... unlike what the hospital would want you to do.
And, in the event you haven't seen it, Psalm and Zoya is a great twin birth as well, one footling breech.
Twin birth is simply a variation of normal.