It could be but like Amante Silvestre said there are many others clues going on at the same time where you could detect specifically if this is a true IOl.
Like was she lending in toward you? Was she smiling while talking to you? How was the eye contact was it flirty? Did she ever touch you during this time? Another thing did she ever make you want to flirt with her at anytime because of how she was making you feel? This can be key as this is a sign of chemistry but if your not confident to move forward it's your loss and learn from it as this girl properly gave you every sign that she was interested.
Putting it all together the answer is obvious I have actually bedded a girl who gave me the lending in toward me and smiling while talking....
You were there and your gut feelings will give you the answers I bet a hundred bucks on it you know if it was a IOl cause your TheGameMaster
LoneSilver