okay
first of all day time and night time dryness are two separate issues
night time dryness comes when the child's maturing body starts producing a hormone that concentrates urine production at night;this can occur from very young, as in DD2 and is not considered a medical issue til age 7 in England; the child has no control over when the hormone starts to be produced.
Things you can do to help in the meantime:
increase daytime fluid intake (milk/water best, avoid red/brown drinks as they can irritate the bladder) - the point is to stretch the bladder volume and thus increase holding capacity and don't withhold drinks after tea time
make sure she's not constipated - this can press on the bladder and cause leaks and wettings
wee/teeth/wee at bedtime (double-voiding)
avoid lifting at night, this reinforces weeing-asleep and is not recommended
wrt daytime wetting/leaking:
you have ruled out UTI, so look at constipation and ask GP about thrush
again, increasing fluid intake will improve bladder holding capacity. you might need to get school onside to encourage her to drink more during the school day. a sports-type bottle for swigging as you leave school each day?
good luck
oh, and shower/bath in mornings for social reasons, we all remember going to school with the smellie child 