It looked like about 2mm of intestince where sticking out. It may be the worms that somebody mentioned but I thought they needed a crustacean to grow and I have none in my tank. I isolated the fish and she died two days later.
Could've be birth/still birth complications. Very common. When you touch something hanging off a fish and it moves on its own is when you have to worry.
i would think it to be camallanus worms....the lumpy belly on the female guppy and the red object extending from the vent makes me believe that is what it is...
not to mention that guppy fry do not have color when born...
had embers dissected the female after it died i think she would have found bunches of the worms...