PP 46-47 of The Pretender: Marco is griping about never getting any time off. Rachel says "When do we get you to shut up? When do we get to switch you off? I mean, good grief, Marco, you act as if you have something better to do. Before we became Animorphs your entire day consisted of figuring out which girl to annoy next."
Marco grins and says "Now I always know which girl to annoy next", and puts his arm around Rachel and lays his head on her shoulder! This is a boost to Marco/Rachel shippers! Do you know of any other indications of a Marco/Rachel ship?