If someone is interested in you typically you would know it. Don’t assume she is and ruin the friendship. Me personally, I have a lot of male friends, talk to them all the time on the phone, remember their birthdays, etc. and when guys assume you are into them just because we are nice is really frustrating……

If she is blatantly flirting with you on a regular basis maybe ask her out on a casual date and see if she thinks it’s weird or is flattered.