Here are two of the clearest pictures that we have managed to get to show the differences between a female and male dwarf hamster.
In both pictures the hamstes rear end is to the left.
The anus is the opening to the far left and the penis and female openings are to the right. You can clearly see in the male the genital organ protrudes outwards and is a greater distance from the anus  than the female opening is in the female. The female opening is not only closer to the anus but does not protrude outwards.  These picture were our baby dwarf hamsters at six weeks old.

  

We took these pics of the teenage pups, which are now very obvious which gender each is

Those are good shots and very clearly show gender. It is still hard in the younger ones isn't it. Some are not so clear either.  :)

Too true!  One of our boys was DEFINATELY a girl right up until s/he was 6 weeks old!!

I swear they change gender in the basket on the way up to the pet store. "They were all boys when I left home". Because we sell so young they can be displayed together in one cage. They go straight from mom to the store and are often sold within a week or so. Very tricky these dwarfies, I sometimes wonder if they can change gender or can they disguise themselves when they want to?::)

Elly has been really really odd over the past 15 mins. They have a "chew chube" (its ment to be spelt chube) which they certinly have chewed - it has odd holes everywhere! She decided to take them one by one over to the tube so that all 8 pups were in the tube, she kept them there for about 10 mins then took them all back after getting really stressed after they kept crawling out the tube. We had just found when there was only 2 left that only the bottom half of one baby was showing - we thought she had eaten it. Then I lifted up the tube and figured that the baby had got its head through a hole on the bottom of the tube and could hardly breathe, it was cold but its mouth was open taking deep breaths. Of course as soon as we saw it we picked it up and studied it, eventually we put it back in the coconut with Elly because we figured she would know what to do better than we would. Hopefully it has taken some milk and is breathing better now - I do hope he/she is ok.

Managed to get a good look of the new babies.  All EIGHT are alive and well which is a relief after last night when we thought one of them was taking its last breath after being crushed under the chube. :)

She thought the chube would be a good nesting spot and then moved them when she realized there was a problem. Good for her and good that you found the baby in time. I check my litters and return babies to mom all the time. It is so easy for one to get lost or in your case, stuck. I am glad of the happy ending and so is Elly. They know if they lose babies and it stresses them. It takes all of us to raise the babies here. it is too much for mom alone. :)

Its funny, as if she counts them. The babies are all in their own cage now, running madly! They are so funny, always piled on top of each other.

thank goodness!!! i just got a winter white hamsetr naemd petals (shes a saphire) and  iwas starting to freak out because i thought she  might be a boy

You must post a picture of your saphire. These are colors I have never seen and I would like to know what they look like. I am glad she turned out to be a girl. :)