Dear Laurie

In France, terfenadine, ceterizine and loratadine can be used in
breastfeeding women. They have a short half live (apart from loratadine),
and pass very few in milk. When mother is breastfeeding a little baby,
better to look at the baby, in case... There is, actually, very few study
on these drugs. Loratadine is  used in France in children from 2 years.

In the case you have, with a 3 years old, I think there is really no
problem.

Hope this help
Kindly
Françoise Railhet
LLL France Medical Associates program