Several patients in my practice have shipped milk home
while they were on the road. Several well-known express mail
companies (ha -- a pun!) routinely handle foodstuffs packed
in dry ice. Have your patient contact one of them for details.

If she is staying at a hotel, she can inquire of the concierge if
the hotel can arrange shipping. Some of my clients have
requested a refrigerator in their room so that they can save
up a few days worth of milk for shipping, and the hotel staff
takes care of packing and shipping (for a price!)

Another option is to freeze the milk during her time away and
carry it home with her frozen. She won't have to freeze the
most recent milk, and the frozen milk will help keep the
refrigerated supply cold. She'll need to arrange for freezer
space where she will be staying. (Hotels can usually do this,
especially if the bottles or bags are stored in a leak-proof
cooler bag or box.)

Margery Wilson, IBCLC
Massachusetts Institute of Technology
Medical Department
Cambridge, MA, USA