Hi N.,
There is some truth in everything these ladies have told you. Febrile seizures are fairly common. I had them. My now 14 year old had her first at 14 months also from an ear infection I didn't know she had. Febrile seizures are, for the most part, not life threatening. You need to be very attentive to your little one. I believe that mother's have a "sixth" sense knowing what is going on. After my daughter began her seizures, we found a lake of moldy water under the rental house we lived in. The environment was dangerous. Fevers come from infections and things don't normally get infected unless there is a reason. If the child has a strong immune system some of the outside stimuli is fought off. Remember things that don't normally bother you can harm a child. Chemicals outgas and toxic fumes are heavier than air (they go down to the floor level where your child is). A small amount of mold or mildew might not bother you but your little one that has smaller lungs and breathes twice as many breaths a minute and takes in twice as much you will.
Don't let fear take over but by all means check out your house and the places your child goes to on a regular basis. I wish I had known this when my girls were little. My daughter's last seizure was while I was in childbirth with my second daughter. I,like you, was never so scared in my life. I remember my mother's stories about me at that age....
I hope this helps.