xxx:
　　 您好！
　　 得知您母亲过世的消息我深感悲痛。您坚强的度过了那段伤心的日子了吗？
　　 您计划好了回国的时间了吗？请告知我，这样可以便于我安排我的工作计划。谢谢！

Dear XXX,

I feel deeply sorrowful on learning the news that your mother has passed away. I truly hope that you will recover from the sorrow of having lost your dear mother.

Have you got your plan ready for coming back to China? Please kindly let me know so that I can arrange for my work plan here. Thank you very much.

Yours sincerely,

注意：我没有按照你的那句话来翻译：您坚强的度过了那段伤心的日子了吗？没有这么问的，别人也不好回答。不如多一些祝愿的好。