I would be concerned that if you stick around as her friend, you may get friendzoned. But if you ask her to call if/when she's ready, she may forget about you in the meantime. My gut instinct is to make yourself scarce and let her miss you - but I can't say with any certainty that it will work.
At any rate, it's not worth putting yourself on hold for someone who isn't equally interested in you.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.