I also deal with this on the phone on a regular basis.  What I say
depends on the age of the baby and the length/type of separation.  For
infrequent separations and/or older babies who are taking other foods I
suggest cup feeding or solids.  The babies will get enough sucking when
mom is around.  I don't have a good answer for the young infant who
doesn't like a bottle.

Sarah

Sarah Friend Barnett   LLLL, IBCLC
Bronx (New York City), NY  -  [log in to unmask]
" You are not obliged to finish the task,
 neither are you free to neglect it."       R. Tarfon