"It is rather impressive, isn't it?" you say proudly, looking at your mountain lion form in the mirror. As Jinn steps back, you move next to the bed and put your front paws up on the bed, just to get a better idea of your size. You are spellbound by how sleek and muscled your feline form is, especially considering your human form was rather soft. Speaking of your human form...
As reluctant as you are to do so, you had better change back. Not for good, but just to make sure you knew how. After all, if something went wrong, you still had two wishes left to correct it with. No sooner said than done, you rapidly change back completely into your human form. Your stark naked human form. As Jinn looks on with that vaguely amused grin on her face.
Even though it's not like you're naked in public, you still feel your cheeks heat up as you blush in embarrassment. After all, bent over with your hands on your bed and your bum in the air is not the most modest position. Now that you know you can change back to human, you quickly sprout fur all over your human body, trying to cover up your discomfiture. After a thought, you change your ears back to triangular ones and return your tail to its rightful position as well. Not for any particular reason, it's just that you like it.
"Hey Jinn, now that I think about it..." your compromising position brought a thought to your mind. "Uh...what happens if I...get pregnant? You know, would the babies be human or mountain lion...or shape-shifters like me?"
"Ah, a good question, Master," Jinn evenly replies. "You did not specify that the trait would belong to your descendants as well. You can always change that with another wish. However, as the world currently exists, it would be hard to find someone compatible for you to procreate with and produce shape-shifting offspring. Therefore, instead, it depends on who impregnates you."
"You mean..." you pause, a little dumbfounded at the possibility.
"If you are impregnated by a human, the offspring will be human, no matter what form you are in," Jinn nods. "Similarly, if you are impregnated by a mountain lion, your offspring will be mountain lion cubs."
You sit on your bed, your tail twitching from side to side as you are lost in thought. It seems this wish is more complicated than you assumed. Should you throw caution to the wind and just enjoy the wish as is? Or maybe you should put some fail-safes in place just in case something goes wrong.