3. Laura's grandmother was the only child in the family

Solution:

The text states: 'Her mum and dad were acrobats and they took her into their performance. The public liked the cute little girl, and Amy (yes, the elderly lady was just Amy at that time) enjoyed wearing glittering costumes and getting applause. What she didn't like was wearing a wigl and a clown costume, but her parents often got her to take part in her twin brothers' clown performance.' The mention of 'twin brothers' indicates she had siblings.

Answer: 2) False