Can we act like adults please?

I don't know how many times I want to say this to one of the sales people at our company. She is my age, 50 years old.

Our boss sends all the sales people their goals for the year and expects them to achieve their goals. They get serious amounts of bonuses. In addition to their sales goals, there are a couple of apps that they must use. If they do not, they are fined by a small amount deducted from their bonuses.

So, this year, she did really well and earned a bonus of say USD 30,000 (that is not the real number). However, since she did not use one of the apps required, USD 750 was deducted from the above number. A normal adult would say "it was my fault, now I have to make sure I pay attention to these things" right? No. She has sent whiny e-mails to our boss and he put his foot down. He forwarded those messages to me saying that he had no intention to budge.

I went up to him and asked if he had conveyed his message openly. He showed me the document he has sent her at the beginning of the last year and even forwarded me that message.

So, today I had a discussion with her and I scolded a 50 year old woman that she was acting in a childish manner and she keeps doing this even when she knows that our boss loathes this type of behavior.

Whenever there is an issue that she is not right, instead of owning the failure, she whines and sometimes even cries. I just cannot comprehend why she is like this.

She keeps blaming other people, claims she did not know such and such thing, did not understand it that way, etc. Truly a baby! How do you handle such people?

Arrrghhh!