I need dating advice bad.

Hey everyone I need help. I'm a 6 foot 4 male and I just started talking to this Asian girl. Asians are my type and she's super pretty. But there is one problem. I hung out with her for the first time today and she's 5 foot. Whenever I'm around her I get little sister protector vibes and she just reminds me of my sister....not in a weird way obviously. We've been talking for a while but she thinks our dating relationship has started but I haven't yet. What do I do? I don't like short girls but I'd give it a chance. I just don't know about this little sister thing tho.