B.M.
my daughter had the lymph nodes 'bumps' that took a couple YEARS to go away after her year long bout with strep throat when she was little. They didn't bother anyone but me (who was in an almost constant state of panic wondering if she had any number of rare but horrible diseases - all of which were NOT true, so if the Dr is not concerned take his advice and try to not worry).
I am wondering.... did the Dr check for mono? I know is the 'kissing sickness' or whatever and 19 months would be kind of young, but he might want to check it out if she the other symptoms and its NOT strep or tonsilitis.
probably they will remove the tonsils and adenoids (if she is snoring badly at night) - not sure what age they do this, but my nephew had his out at like 3 and by now it's almost an outpatient procedure - he was admitted, but released that night.
Good luck.