291.
M: Hi, Ms. Rowling, how old were you when you started to write? And what was your first book?
W: I wrote my first book when I about six. It was about a small tiger. And I've been writing ever since.
M: Why did you choose to be an author?
W: Well, if you want to achieve happiness, step one would be finding out what you love doing most. Step two would be finding someone to pay you to do this. I consider myself very lucky to be able to support myself by writing.
M: Do you have any plans to write books for adults?
W: I suppose I might write one. But I never really imagine a target audience when I'm writing. The ideas come first. So it really depends on the ideas that grasp me next.
M: Where did the ideas for the Harry Potter books come from?
W: I've no idea where the ideas came from. And I hope I'll never find out. It would spoil my excitement.

答案解析：
(1) 正确答案为C。根据I wrote my first book when I about six. It was about a small tiger. 我六岁时写的第一本书。那是关于一只小老虎的故事。可知，罗琳女士的第一本书是有关动物的，因此C项正确。
(2) 正确答案为A。根据I consider myself very lucky to be able to support myself by writing.我认为我能以写作为生很幸运。可知，她认为她的幸运的原因是能以写作谋生，因此A项正确。
(3) 正确答案为C。根据I've no idea where the ideas came from. 我也不知道点子来自哪里。可知，罗琳女士也不清楚《哈利·波特》故事的点子来自哪里，因此C项正确。