Jenny's bedside clock is at 6:10 before the doctor is called. Then 6:45 when the doctor examines her, and then back to 6:10 as the doctor leaves her room.
When Ben leaves Mrs. Gann and goes up to his apartment, it only takes him about 3 steps before you hear his door open and close, but when Jenny leaves to go up the Ben's it takes her about 15 seconds and a flight of stairs to get up there.
As two "identical" girls walk out the door, one is visibly taller than the other, and has noticeably darker hair.