A belated edition to the toddler-cookie debate.  My son was diagnosed at about 15
months with milk/egg/wheat (and other grains)/soy etc. allergies.  We didn't
stop eating everything he could not eat, figuring that the real world would
offer him constant temptations.  Neither did we want him to feel constantly
deprived.  He learned early on, I don't know how, to identify 'wheat' (his
worst allergen) products, and points to bread/cake/and cookies and says
"Wheat! Wheat!"  He has never shown much interest in snatching any of these
foods, understanding they make him "itchy".  He has a lot of special "Nicky"
foods/snacks, like rice-cakes, corn chex, strawberries, and can eat some
candy and fruit at birthday parties.  With a 15 month old, it sounds more like
"forbidden" food behavior than a real craving for 'cookies'.  Nicky did other
forbidden things at that age (which he has since outgrown thankfully) like
hair-pulling, throwing things in toilet, etc.  The only advice I would give,
(and with a grain of salt since all babies are so different) is to boost the
special treat foods you have for this 15 month old.  Food's psychological
dimension is important especially if you ever use cookies as a reward or as
comfort food for your daughter.  Good luck! I'm soon to be a mom of 2 and am
sure I'll get my share of sibling conflicts too.
Susan.