Valli was a mature girl and …

Yes Valli was indeed a mature girl. She could make correct decisions as we have seen in the chapter. She was very clever. Instead of asking others about the bus journey, she carefully listened to the conversations of people who regularly used the bus. In this way she was able to collect some information regarding the bus journey. She carefully planned how to save money. She resisted all the temptations which ordinary children can't do. She knew that her mother used to take nape at one o clock. So, she chose to go to bus journey at that time. She was able to go on a bus journey alone. She didn't want help from the conductor to get on the bus, she herself got into it. She didn't accept a stranger's offer( of conductor) .

acha hai