Would it hurt a human if they drank dechlorinated water?

We got a new betta fish today, and before we left my dad filled a jug with water and put the water conditioner (dechlorinator) into it and said "Don't drink out of this jug, it's the water I'm gonna put in the fish tank" and he drew X's on the back. So we left and got the fish and my dad had already put the water in the fish tank and there was a little bit left and my mom completely forgot about it and took one sip of the "fish water" Will she be okay? She said she feels fine, and I don't think it's gonna hurt her but i wanted to be sure. thanks in advance. :)