My daughter of 10 years old has been queefing through out the day i.e farting through her virgina. what can this be?

get her to a pediatrician immediately

This could be simple air in the vagina after exercise or manipulations of the vagina, but if she's still passing gas through her vagina, & especially if there's fecal matter also passing through, the pathology is usually a sinus tract from the colon into the vagina. In view of this possibility I recommend consulting a gynecological surgeon for evaluation if symptom persists with no obvious cause.