Hello, Your's daughter's tonsils are enlarged, no doubt, might be due to MONO, reason may be some bacteria.She is feeling extreme pain so pl try hot saline gargles, with some local iodine
type solution. Nyquil
produce mild sedation and this will give relief to your daughter that is prime important at now. 2ndly disease is not serious so please don't take unnecessary burden. Swollen tonsils will diminishes in short period. For pain consult your physician he will prescribe some potent painkiller.