「ありがとう。嫌いなわけではないよ。お腹が一杯なわけでもないよ。ただそんなに一杯は食べられないだけだよ。いつも分けてくれてありがと。うれしい。」を訳しますと
↓
"Thank you. It's not that I don't like it. It's also not that I am full. It's just that I can't eat so much. Thank you for sharing the food with me always. I'm happy."
It's not that I don't want any, it's just too much for me.
この場合、次のような言い方ができますよ。
ーIt's just because I can't eat that much.
「あんまり食べられないだけだよ」
ーIt's not that I don't want any, it's just too much for me.
「欲しくないんじゃなくて、ママには多すぎるんだよ」
ご参考まで！
アメリカ合衆国 
カナダ 
