one of these things is not like the other

aunt emily came for a visit last weekend and while she was here, she took a walk around the farm to see the animals. she helped feed the cows and gather eggs, and saw our very pregnant goats. we were hoping that they would kid before she had to leave, but they waited until the day after she left. josh called me at work to tell me that kiora had 3 kids, but only one survived. when i got home at 10:30, i saw that rosalie had also had 3 kids. this year we've decided to quarentine the kids at night and re-unite them after morning milking. luckily the singleton is the only male, so it's easier to match them up with their moms. can you tell which one is different?