Note: Tortoises are  land-dwelling while turtles are aquatic

She sat on the back of a turtle
then said  " Go Go Go !"
While he on stumpy feet
       trumbled and humphed
"you are mighty hefty !"
he configured.  
She guided him to the water
then said   "Go Go Go !"
I know you want to, what is stopping you?
"You've mistaken me for a tortoise
little girl !"
She turns around and leads him to land,  
and together they sit in the sand...