They will ask how you know your mother is your mother
I hate that one! Besides, despite a whole bunch of pictures of my day of birth and hand prints and evidence that she's probably my mother, I'm still
more willing to consider the possibility that somehow she might not be my mother than the average Muslim is willing to consider that the Quran might not be the work of God.
But yes, Zeus, you are about to embark on a terrible, endless journey of listening to one argument after another from theists. If you disprove one of their arguments or claims, you'd better believe they're going to come back with another one with equal or less merit than the one you destroyed. Most of them use flawed analogies. Some of them are Frankenstein monsters of old Christian cosmological arguments or theoretical concepts in physics. Some of them use chocolate bars. There are infinite places for them to hide. You're in for an annoying ride...