lady's-thumb

例句：

1. 1.She uses her lady's thumb to write elegantly.
   她用她的女式拇指优雅地写字。
2. 2. The artist used his lady's thumb to paint the portrait.
   艺术家用他的女式拇指画肖像。
3. 3.The old lady's thumb is a valuable heirloom.
   老太太的拇指是一件珍贵的传家宝。