The dragon glass weapons they are making at winterfell are meant for the dead, but if a human gets one in the heart, will they turn into a white walker? Maybe it's not that simple, but if they hit Cersei's army before having a chance to retool, it could get interesting.
I could see Bronn bring the crossbow to Tyrion, he ends up shooting Cersei with it and a dragonglass bolt, instant Night Queen.
I hope not. I think it would just kill them. 'Dragon glass' is made by melting volcanic rock, so it doesn't really have properties associated with cold and winter. The Children of the Forest made white walkers by imbuing the glass with their own magic. If there are any Children left in Westeros, they'll be on the Isle of Faces in the God's Eye.
shareYes, I'm pretty sure only an enchanted piece of dragon glass can make a white walker. Regular dragon glass (i.e. obsidian) can be used to kill them possibly because it's the same material. They never said why Valyrian steel is also lethal. The secret to making it is lost, even the maesters don't know what went into it or what process was used.
The Children already tried stopping their renegade creations and couldn't. There seem to be small populations of them left but no great legions waiting to march into Winterfell and help out. I don't think. If they have a plan there aren't many episodes left for them to come out of hiding and execute it. Guess we'll see.