Where diabetes diagnosis is concerned, it is not a simple matter and many people have their types misdiagnosed. I would assume that gestational is more common than type 1. Traditionally type 1 has been viewed as 10% with type 2 being 90% of diabetics. However, it is becoming known that 10-20% of type 2's are actually misdiagnosed and are type 1 or LADA. I myself was mistakenly diagnosed type 2 at 58 when I was in fact LADA (Latent autoimmune diabetes in adults, a variation of type 1) As for the general age of a person with type 2, in general they are older, but as obesity has become an epidemic in the U.S. it is more common for people to be diagnosed with type 2 as children.
Bottom line is if anyone is diagnosed with diabetes they should receive antibody testing to determine type (although you will have to convince your doctor of this as it isn't yet common practice)