Not sure how tall your little one is but the Nuthouse roller coaster is a height req of 36" so that is a possiblity. I think the Simpsons was a 40" Height requirement and same with Jimmy Nutron which I think my nephew hit when she went but it varies by kid how tall they get when.
Over at IOA...
Jurassic park is 42" - Water ride that is pretty relaxing except one big drop and a cpl of dinos but nothing that jumps at you so not too scary.
Flying Unicorn - I think was a little coaster is 36".
The P Flyers are 36" - High in the sky type thing might be scary to some kids but looked cool and it rides 2 people so you or DH behind.
Spider man 40" - 3D Dark ride was pretty cool and wouldnt be too bad for a small kid.
High in sky Seuss Train 34" - Easy ride just goes over Seuss land and tells a story like thing would be good for a little kid I think.
One fish, Two Fish, Red Fish, Blue Fish - No height req. Dumbo type ride.
Cat in the hat - No heigh requirement for this either and I rly enjoyed this it does spin a little bit and tells the story of the cat in the hat.
The website also suggest camp Jurassic but I have no idea what is there we didnt look at that.
Hope this helps and have a great time on vacation.
~Jonny