I think that the ultrasound should tell the gender of the cub. Real ultrasounds do, and it might help users make space for males instead of being like “oh bleep”, I have a male.

Additions:
a small 10 sB fine to see gender
A small 15 sB bonus for male cubs if they were originally males and are still males to help afford them
This feature should be available for the last two days of pregnancy
For 300 sB, the gender of any one cub per pregnancy can be changed
On the last day of the pregnancy, it should also tell if they have mutations for 100 sB
20% chance of being incorrect (if they are incorrect, there is a 80% refund