why does Charlotte who is unemployed have a nanny?

Because she is rich and would rather walk around the kitchen in designer label dresses.

Because she has two kids under the age of six. That requires a hell of a lot of attention, time, and energy. I used to judge stay-at-home moms who hired nannies or help. But after seeing in real life the amount of stress and frustration being a mom entails, I changed my opinion. Even if a mother is not working, it is incredibly taxing to spend your entire day with two little ones and not do anything else or have a break.

Now, I was confused as to why she would need a full-time nanny who lives with them. Also, I think she was naive in her fairy tale visions of being a mother and probably did not consider the unpleasant realities that come with being a parent. But I do not judge her for hiring help. Kids at that age are a handful.

I knew a woman who had twin babies. Her husband worked. She did not work and stayed home with them. Her mother came to stay for awhile to help out. Her sister who was living there at the time also helped out. It STILL was not enough. When one baby was full, the other was hungry. When one was asleep, the other was awake.

I have a friend who has two sons, aged 3 and 1.5. As soon as she gets home from work, they demand every spare second of her attention. Her husband's too, but mostly hers. She can't read, exercise, or watch a movie because they'll come and bother her. I think her work is her escape.

I just cannot imagine having two young children (let alone one) without any help or at least something else to do, like work or other activities.

It's the common practice in her social class. Also, she was part of the PTA so she was not really unemployed, she just did not get compensation for her hard work.