Nae,
19 minutes
19 hours
19 days
19 weeks
19 months
(of breastmilk)
it's all good hon.

i am assuming your goal, was to let your child self wean.

breastfeeding is dynamic, things change and goals change too.

i think it's more important that the weaning of your child, involves your family making that decision, not a medical person who is not in your family.

first, make sure you get good info.
doctors do not study bf-ing in med school, so i would seek out info from people who ARE educated about bf-ing e.g Barb Glare, who has already responded, and the ABA.

second, make your decision based on the info AND what suits your family

you're right, it's a big decision. and it's something to come to terms with, a big shift in your family dynamic.

it needs to feel right for you and your DD and your family. not something to be rushed/bullied into, due to uninformed people

and yes, 19 months is terrific - IMO, ANY bf-ing is terrific. I would tell you the same, if you had fed her for 19 hours. it's not a competition, there is no magic number, it's what happens for your family.