Not likely. She would have exhibited the signs of Turner’s syndrome, as described in my post earlier in the thread. If she was a normal XX female, then they were fraternal twins, though they may have shared a placenta, as is the case occasionally in non-identical twins.
Heh. My brother was born eight and a half years after I was. When I was a preteen, my hairstyle was a short pixie cut…and my brother also had the same haircut when he was growing up. In our old childhood photos, we sometimes have problems telling which of us was which, unless there are other clues in the picture. For instance, our sister was between us in age, so if she’s bigger than the child in question, it’s a pic of Johnny, and if she’s smaller, it’s a pic of me. Of course, if the child is in a dress, it’s me, because I wore dresses a little more frequently than Johnny did. Although I was every bit as reluctant to wear dresses as he was. 
However, our faces were just about identical. If we’d been born twins, I imagine that we would have been mistaken for each other frequently, as not only did we look alike, but we had (and still have*) very similar interests and hobbies.
As adults, we don’t look nearly as similar, partly because of sexual hair differences (we still have similar hair lengths, except that these days it’s Very Long Indeed). For instance, Johnny has a fine beard and is balding on top, though the hair that he’s managed to keep is very fine and wavy. I have a lot of gray in my hair. Our faces have a definite family resemblance, but he has a much more masculine chin now, and a generally more angular face.
*When we get together, we commonly discuss books and authors, and find that we’ve been reading the same books!
I think a lot of people don’t understand what “identical twins” really is. I worked with a guy once who had a twin sister. Another co-worker, hearing about the twin sister, said “Oh, are you identical twins?”
I laughed. I thought he was joking. No, he really wanted to know. “They can’t be,” I began, when I was interrupted by the twin.
“But we are identical twins!” he said. “We look exactly alike!”
True story.
Anyway, even people who should know better often don’t.