You sit down in the chair next to the cardboard standee of Dr. Terrific, and also spotted that more needles that were in the booth with Brenda have injected into her body while she was still standing, and still had the muscles of a female gymnast. You were surprised that she didn't become too big for the machine too.
Seeing how she had the perfect body for a superheroine, you spotted that while she became buffer, and taller than the wrestler girls at your school, you could definitely get protection from Brenda if the school bullies plan on robbing you. You could also guess that the second needle you saw poke her would give Brenda her superpowers while she was able to use them, and hopefully not cause property damage. You could also see that Brenda didn't choose any costume, so she would go for a custom look.