[Nagoyankee]

「お返事お待ちしております,そしてお体を大切に, だけどあなたの手紙の日本語を書いてください。」

That looks pretty good. Like the word だから I mentioned earlier, the word だけど sounds highly colloquial, too. The bigger mistake would be the use of あなた. I know you just translated 'you' into Japanese. But we rarely say it. We use the other person's name + san. 書いてください could sound a little demanding so I will change that, too.

I would re-write it to:

「お身体を大切に。お返事お待ちしております。鶴見さ んのお手紙もぜひ日本語でお願いいたします。」

It may look as if I changed everything, but I really didn't.

To get the word ウィーク, you only need to type WIーKU on the Japanese input mode.