Sounds like while she insert a probe in a cloaca she does not know what she is doing which you need to keep in mind.So I took her to the vet and the doctor believes it is a female, she did probe her, I'm not 100% sure how experienced she is but I'm assuming she would have to be certified to be doing such a thing as a doctor, but she said because she is so small it was hard to tell?
Why am I saying this? The bolded part of your post, they are VERY easy to sex at that age if you know what you are doing.