One of the pictures in my links in previous posts shows a similar picture of the two vent openings up high near the tail. Pictures of her later on would be good to compare.
I too would like to see a picture. As you can see there are people who have these chicks and ask what to do. With pics of yours and with updates later on how she gets along, functions, and hopefully lays eggs, we can keep showing these threads to others.
Here are a few more, including a grown rooster:
https://www.backyardchickens.com/threads/chicken-with-2-vents.1096954/#post-16862930
https://www.backyardchickens.com/threads/one-chicken-2-vents.1024053/#post-15894691
I would not put her down. There have been numerous threads of chicks with 2 vents here on BYC who have survived, and even laid eggs into adulthood. Make sure that she is pooping out of one of the openings. The other side could be her oviduct opening. Here is a picture from one thread where...