Missing ovary (child)

My daughter (5 yrs old) recently had a stomach ultrasound because of stomach aches and development of pubic hair and body odour. The ultrasound was all clear but they couldn't find her left ovary. At the time and at the follow up GP appointment the general consensus was it is probably there they just couldn't find it at the time. Anyway I have just received a letter in mail for a review and it is relation to the missing ovary. Doctor said nothing about a follow up but I'm guessing he may have changed his mind and decided perhaps it needs to be found. Anyway just wondering if anyone has a daughter that has had a missing ovary - what was done? What was the end result? Google is not helping me - plenty of women saying they have had child with only 1 ovary.