new weed user here. it seems to have no effect?

Hi everyone

so my sister got me some weed the other day for me to try out. i bought those little pre rolled cones, grinded my bud and carefully put it in. i wrapped up the end and smoked it.

i took a hit or two, waited 20 minutes. nothing. not even a mild buzz. i tried smoking more, I sucked in deep till I felt the heat on my lungs and started coughing and I did that several times, and still, absolutely no effects whatsoever.

and it's not just me. my girlfriend, who has also never done weed before, took around 15 hits in an afternoon. she said the feeling was comparable to having a beer. My sister tried a few hits too, with the same results.

Why is this? What could I possibly be doing wrong? the weed looked fine, I think. I'm burning it up and inhaling the smoke, so why isn't it making me or anyone else high?

i attached a pic of my weed and a joint. did my sister just get scammed? please help!