Step 1: Understand the situation.
When Jansie reached Sophie's street, she was filled with excitement. She had just received an invitation to Sophie's place, which was an unusual occurrence for someone like her, who came from a modest background.
Step 2: Direct quotation.
Jansie said, "What a beautiful street!" as she observed the contrast between Sophie's luxurious house and her own humble living conditions.
Step 3: Conclusion.
Jansie's reaction shows the disparity between their worlds and her admiration for Sophie's affluent lifestyle.
Final Answer: \[ \boxed{\text{When Jansie reached Sophie's street, she expressed admiration, saying, "What a beautiful street!" She was taken aback by the difference in their living conditions.}} \]