My DS has been doing green since he was 5 and has always been fine. The motion isn't intense, but if your child doesn't like enclosed spaces, she may not like it. You mention she is brave, so I would try it. You may want to let her know that if she needs help reaching the buttons or if she doesn't reach them in time (if they still have the "engage now" command on the new ride) it will be ok. No, your module will not crash on Mars (my DS was scared he wouldn't press the buttons on time and something terrible would happen - let's when we had to let him on the secret that it wasn't real, LOL!)