Dear Judy,
I've worked with a lot of mothers who "need" (often their perception) to go
away from 2 days to 2 weeks.  Your suggestions to her are good ones.  Of
course the best solution, as you suggested to her,  if at all possible is for
her to take baby and grandmother with her, park them at the hotel and
continue the same routine of expressing milk if she is away for a feeding as
she does when at work.
It may not be possible for her to express enough milk for the entire 5 days
with this short amount of time left.  She would have to ask grandmother to
use some formula, either daily to stretch out her milk or when her milk ran
out.
Mother can express milk while gone trying to maintain her supply.  Almost all
the mothers I have worked with who do leave the baby come home with a greatly
reduced milk supply and must work to build it up again when they are come
home.  Does she have a pump or does she hand express?  She would do the best
with the most efficient pump (double if possible) that you have available
unless she is a master of hand expression.   Stress she should express as
much as possible to keep up her supply, during her breaks and often when she
is in her hotel room.  She can use a cooler and ice and save it if possible,
or throw it away. (sob)  In the US one mother I knew of "Federal Expressed"
her milk home on dry ice.  It arrived safely and kept Dad from having to use
formula for their very allergic baby.  Is there anyway she could get dry ice
in Mexico and have the milk she expresses for the first couple of days flown
back home to Honduras?  Arrangements would have to be made to meet the plane
and get the milk to Grandmother & baby.  That might save them from using
formula.
THEN, she should be aware that baby will either cling to her and want to
nurse constantly when she gets home, which will help get her milk supply back
up if low, OR baby may look at her like "Oh there you are!  You think you can
waltz in and out of my life, do you?  Well I've learned how to get along
without you now!"  AND refuse to nurse and ignore her.  This can be treated
like a nursing strike with lots of skin to skin contact, bathing, sleeping
with baby, trying to nurse when baby is sleepy, etc.  She would need to
continue to express her milk until baby resumed nursing well.  Usually baby
will resume nursing, then "nurse mom to death" for the next couple of weeks.
 She does need to know baby might refuse to go back to nursing and be totally
weaned.  Unfortunately I have had this happen to the mother's dismay.  She
also needs to hear "the truth" that the baby will miss her terribly.  This
can be stated in a very factual way, and may help sway her in favor of taking
the baby along.  She is worried about what people at her job will think about
her taking grandmother and baby along, so she also needs to think about what
baby is feeling and thinking.  We all need  to be baby's advocate,
truthfully, factually.  It is non-professional not to tell the truth, as many
do to moms.  I sometimes find it useful to say to moms, "Maybe noone else has
said this to you, but your baby will miss you terribly and won't understand
your long absence. To a baby this amount of time seems like forever, and
he/she won't understand that you are coming back.  You may see signs of
stress such as clinginess, fussiness, refusal to nurse or nursing all the
time, when you return."  Then you help the mother make the best preparations
she can for maintaining her milk supply, and getting nursing going again when
she returns.

Good luck, and let us all know what happens.
Jane Bradshaw RN, BSN, IBCLC
Lynchburg, VA