Does my two year old have autism?

My daughter has met all of her milestones on time. She is developmentally on track according to my pediatrician. A friend of mine who has a cousin who is autistic pointed out some behavior she thought was odd. She commented on the fact that she likes to line up toys (crayons, , blocks, etc) and she has never had any sort of separation anxiety. (She does not go to daycare) She also likes to obsessively pick lint off her pj's, and fuzz off the floor. As I was doing some research trying to find out if my friend has some insight i don't, or is just paranoid because her cousin suffers from this, I read about some other things that now have me panicked. She walks on her tip-toes if she doesn't have shoes on, she is very independant, and friendly to strangers, with little fear of anything, she is confused between shaking her head yes and no, and seems to be very tough (reduced sensitivity to pain?) Although she does not hurt herself on purpose. I have never been concerned about her eye contact and smile responses, although she is very busy and doesn't seem to have much time to cuddle. I have been on the internet driving myself crazy with this for hours.....please help!