"Toutes ces frites pour moi ?"
In real life, yes ; in Duolingo, no because you have to stick as close as possible to the sentence given for translation. Do not forget that the "professor" here is a software and cannot consider too many variants for one given sentence.
By the way, there is no verb in either of these sentences.
Yeah, I realise that now, as Sitesurf previously said, I fell into a translation muddle. More to the point in a proper question in English you require an auxiliary verb so I added it in.
It's not word for word translation but my sentence definitely has the same sense. I do however understand why it wasn't accepted.