If this mother really wanted her child to enjoy the park, she would have checked into it ahead of time to see which rides she could or could not ride. At that point she would have discovered that she would have been able to ride more rides if she had a prosthetic leg, so she should have brought it with them. If her daughter didn't enjoy the park, it's no one's fault but her own.
People get this "I'll be damned if someone's going to tell me I can't do something" attitude too often these days. People need to accept that not everyone can do anything.