It looks to me like you were very close! Here's my translation. Can't quite make sense of the pun about her being 'genuine sisters' in the first sentence. And I would think that Spurgat was the name of the performing group, but how 'krystalnummer' conveys that I can't explain. Until somebody comes along who can clear those up, here's this:

Bonny Sisters is a resident of Fyn and genuine sisters. The whole thing started when she, whom the family really did call Bonny and who had a gift for ballet and acrobatics since she was [8?] years old, got permission to drop out of school and join an artist troupe when she was just 14 years old: the crystal number also famous in Jylland, "Spurgat." With that, the 14-year-old traveled the next ten years literally-spoken around the world, a good training for standing on one's own feet.