What's the best way to determine my snake's gender without probing?

This is fine and no cause for concern. If she has never been housed with a male, the eggs are infertile and can be discarded. As an aside, you can sex a corn snake by gently restraining it and turning it over. Locate the vent and with your thumb, apply gently pressure just below it. If it is a male, this action will make the hemipenes pop out.

Thanks for using Petco Pet Education Center, formerly Petcoach! At least on these pictures, they both look like males. Keep in mind that it is not that easy to determine this based on a picture. This will be easier to determine when they get a bit older as well. Have a great day!

Unless you know the hatch date, determining age is very difficult. There are growth charts but these can be inaccurate since each snake will feed and develop differently. Your best chance would be to contact the store or breeder or have Fred examined by a veterinarian experienced in treating reptiles.

Hello, thank you for using Pet Coach. Sexing them is not hard. I suggest you refer to this article. It goes into more detail then I have room for here on this forum. ( http://www.reptilesmagazine.com/Breeding-Lizards/Sexing-Leopard-Geckos/ ) Hope this helps. Best wishes!

The problem is that these eggs are basically rotting in her. It would not be safe to soak her. The rotting eggs are full of toxins and if any of them leak it could kill your snake. SO your vet is correct in his assessment to have her spayed in order to save her. Please listen to your veterinarian,

It's quite difficult as their shells are very similar. The male has a long thin tail with a slit like cloaca far up the tail. Whereas the female has a short fat tail with a star shaped cloaca close to the body. If in doubt you may need to go to a reptile vet.

Hello and thank you for reaching out to Petco Pet Education Center, formerly Petcoach. A male monkey will have testicles and a female will not. Different types of monkeys will have different features between males and females also. I hope this is helpful!