From the Super Mario Wiki
“That's right, Kylie Koopa's got your number!”
Kylie Koopa is a female pink-shelled Koopa Troopa who appears in the game Mario & Luigi: Partners in Time. She works as a journalist for the Koopa Kronicle, which is most likely a news organization in the Mushroom Kingdom of the past. As a reporter that is always on the lookout for "The Big Scoop", she has a ritzy personality, uses slang when she talks, and likes to take lots of pictures with her camera.
Mario & Luigi: Partners in Time
The four heroes of past and present first encountered her when they were traveling to Yoshi's Island. There they saw her actively snapping pictures and getting information about the Shroob monster Yoob. The Mario Bros. saw her trying to see where the Yoshis were. The babies helped her out and found the Yoshis. However the Yoshis got eaten by Yoob who also found them. Kylie Koopa was even foolish enough to go and take pictures right in Yoob's face. Yoob then inevitably ate her. However, since Kylie was a Koopa, Yoob immediately spat her out. Kylie wasn't seen again until the 4 heroes entered Gritzy Desert, where she told the brothers about the Shroob meeting and about the secret entrance to the Koopaseum. Later she gets kidnapped and tied up by the Shroobs in the Koopaseum and then fed to Petey Piranha. The Mario Bros. rescue her in Gritzy Caves and defeat Petey and Kylie spins away, but not before revealing that Princess Peach was inside Petey, but was spat out. Later on in the game, when it seemed as all hope was lost for the Bros., (Princess Shroob was going to defeat them), it revealed that she was disguised as a Shroob and rescued the bros. Then she finds out Toadbert recovered his memory and they quickly follow the Mario Bros. to tell them. However, she and Toadbert got hurt by The Elder Shrooboid and both got Shroobified: she is turned into a Shroob Mushroom by the Elder Shrooboid She got turned back into normal form (along with many others) by baby tears at the end of the game.
One of the Toads in Princess Peach's Castle mentions having read a book called "Fungicide: The Epic Battle for the Mushroom Kingdom". The book had been written by Kylie. This implies she wrote a book about the adventure of the four Mario Bros. and their battle against the Shroobs.
Mario & Luigi: Dream Team
“You wanna know why I'm here? Glad you asked, boys! Name's Kylie Koopa! Ace guidebook writer for the entire island!”
Kylie returns in Mario & Luigi: Dream Team. She now works in a building in Wakeport where she writes tourist guides. Strangely, although this game takes place in the present day, Kylie Koopa still looks no older than she did in the past. She also doesn't seem to remember the Bros., due to numerous jobs she's had in her career; as stated by Kylie. All throughout Pi'illo Island, Kylie had left blocks with snapshots called Camera Blocks that Mario and Luigi can find and retrieve their snapshots from. Because the snapshots are encrypted, Kylie asks the brothers to decrypt them for her, by rearranging pieces of the image. Kylie times the Bros. when reassembling the snapshots and can be rewarded with Coins or DX Beans if they complete it under a time limit.
During the ending credits, Kylie Koopa is seen taking a picture of Princess Peach and some Toads on Mount Pajamaja. In the group picture at the end, her cap and arm can be seen at the bottom.
Names in other languages