You heard a lot of I love you , but as you know words are the cheapest and they just come out of their mouth. the real meaning will show when you ask her about something more important like borrowing something valuable! thats the moment you can find out if she feels the love or not!
There are signs you can find out about true loves based on science:
Have you ever catch her smelling your pillow when you are leaving for work! you skipped your shower for couple of times but she still wants to lay next to you and be with you no matter why? This is a big trouble, studies has shown that girls usually use their sense of smell in determining a partner.