Nemo-fish

So, several months ago, the girl picked up a "Nemo" toy that she found somewhere & LOVES it. We went to the Aquarium soon after & found Nemo there. With the swimming issues she has had we thought maybe letting her watch "Finding Nemo" would be a good idea. We decided to put it off - the opening scene is pretty scary - mom & babies are killed....not an easy one for a 3 year old. Well, Saturday night Lee & I put the boy to bed early as he was lying on the floor sucking his fingers - it seemed to be time. And we let the girl stay up a little late, eat ice cream sundaes & though Lee & I argued back & forth on whether or not we should let her watch her 1st movie.....we finally decided to go for it. We pulled out "Finding Nemo" & she was SO EXCITED! We dimmed the lights, got our ice cream - fast forwarded through the 1st scene - & pressed play. Well, in the 1st 5-7 minutes a big man, which she calls Spiderman, takes Nemo away from his dad. She looked at us in horror & said, "Is Nemo scared?" We wonder if it's time to turn it off or should we let her watch it play out & be ok......we keep rolling......and then the big shark comes on the scene. I gulp.
She looooooooses it.
Tears ... "I do not yike dis video"
It's off. And the damage is done.
I mean the tears wouldn't stop. We went to say our prayers before bed & she let me know that Nemo is NOT her favorite video & we prayed that Nemo would not be scared. NIghtmares....crying....occasional reminders that she's not a big fan of the orange fish or any of his friends any more.
Anyone else made a fumble like this in parenting???