Why would she always say that I am sooo young?

I've met a girl in an event and it seemed we were hitting it of, but she randomly said that I look so young. And it turned out that I am like 8 years younger than her. Even after that she seemed interested but she was continuously were repeating that I am so young. After this she was mainly talking to me, when she went somewhere asked me to go with her, and suggested to keep in touch. Now I feel like asking her out, but her saying I was young repeatedly throw me off. What should I do?
Why would she always say that I am sooo young?
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