They were not letting moms with infants in slings ride with the infant remaining in the sling. Obviously, as always, unwritten "rules" can change depending on the cast member. I would not recommend just holding an infant on your lap without a carrier holding him/her as this ride can jerk you around enough to potentially let him/her slip. 
She should be fine. You might not be able to play all that well, but you will definitely get the gist of the ride. BTW, you can use child swap on TSM. We've done it before. And I think you can use child swap on ANY attraction.

She should be fine. You might not be able to play all that well, but you will definitely get the gist of the ride. BTW, you can use child swap on TSM. We've done it before. And I think you can use child swap on ANY attraction.
There is room and My son 22 months sat on my mom's lap to start out. But I will tell you that the ride whips you around a little and it freaked him out so for the rest of the ride he clung to me screaming everytime the car whipped. I am sure if the baby is in the sling they would feel more secure. I also say everychild is different so really I am sure the baby will be fine. Have fun.![]()
So, I didn't do my best since I had one had on her.