filly

例句：

1. 1. The filly was a beautiful horse that won the race.
   这只小母马是一匹漂亮的马，赢得了比赛。
2. 2. She rode the filly to the finish line.
   她骑着小母马冲过了终点线。
3. 3. The filly is a rare breed of horse that is not commonly bred.
   这只小母马是一种罕见的马种，不常被繁殖。