Well, it looks Mom is heading to Guangzhou, not Shenzhen as originally anticipated. By train to Hong Kong, it is about 1:45 minutes away and one way train ticket is about US$50.00. The trains are numerous and almost every hour has one.
Mom is taking a lot physical exams together with many shots for the vaccination. She is scheduled to leave for Boston from Augusta, GA on the 7th (Sunday) and heads to Hong Kong on the 11th (Thursday). She will be heading for work in Guangzhou from Hong Kong on the 15th.
Oh, I hope everything goes smoothly!