America votes one the third person being in the finale. In the final 4, the two people who fall below the yellow line get voted upon by America. Which basically means if Ali makes it next week (and Kelly too) and they don't fall below together, they will both be final 3.
Ali still can lose several pounds. She can get down to 117 pounds (being at 50% weight loss) and still be at a healthy BMI. She said her weight on a radio station (her current weight), and the person has yet to report what she said because they didn't know how to use spoiler tags but I will report back as soon as I get the info
ETA: You guys have to remember. Unless Rodger is final 3, Ali has this in the bag. There is ZERO chance the brothers can get down to 145 pounds or less (which would be at 50%) So if Rodger gets booted, Ali will win.