The queue order is given directly: Jack is 1st, Jill is 2nd, Mary is 3rd, and Asher is 4th.<br><br>
The person before Asher (4th) is the person at the 3rd position: Mary.<br><br>
Check: 1st = Jack, 2nd = Jill, 3rd = Mary, 4th = Asher. The person just before 4th is 3rd = Mary.<br><br>
Final Answer: Mary