Please take care of her、please take good care of herのどちらをよく使いますね。
例えば、
If I think of something happening to her when we can't see each other,
しばらく会えない間に何かあったらと思うと
I can't stop worrying and feel like my heart is going to break.
心配でたまらなくて胸が張り裂けそうです。
Please take good care of her until the day that I can visit
次また私が来れる日までどうか彼女をよろしくお願いします。
ご参考になれば幸いです！
"どうか彼女のことをよろしくお願いします。"
- Please take care of her. (I leave her in your care.)
・しばらく会えない間に何かあったらと思うと心配でたまらなくて胸が張り裂けそうです。次また私が来れる日までどうか彼女をよろしくお願いします。
面会の規制が解除されたらすぐに連絡して下さい。
When I think about what could happen during the time that we are unable to meet, I get so worried that my heart feels like it is about to break. I will leave her in your care so please take care of her until the next time I am able to come. Please contact me once visitors are allowed.
アメリカ合衆国 
