Why didn't Valli want to go to the stall and have a drink? What does this tell you about her?

Valli didn't want to go to the stall and have a drink because she didn't have money for it. She even tried to refuse the offer of a treat by the conductor. This tells us that she was a wise girl and had self-control on her feelings. She also knew the value of money and was righteous enough to avoid taking a favour from strangers.