After graduation, Martineau began working as a model. Fearing that her condition would lower her chances of getting a deal, Martineau would hide her condition by arriving at the modelling agencies early and leaving late so that she wouldn't appear "breathless". Because she had a co-ordination problem when walking (due to a vitamin deficency), she wore shoes at the interviews. She was eventually signed to work for an agency that specialises in models with "unusual features". Because she was only tall, Martineau did not model on catwalks. Instead, she did photo sessions and appeared in teen magazines such as Just 17 and Jackie.