HOUGHTON — Between going to school daily, being involved academically with clubs, soccer in the summer, volunteering at the Portage Lake District Library and dance classes after school, it’s incredible Maria Sliva can find time for extra activities or even an interview. But the one thing the 14-year-old — who has often been called “a remarkable girl” — will clear her busy schedule for is her work in Mexico. Sitting at her kitchen table in Houghton, clutching a colorful handmade friendship bracelet in one hand and flipping the pages of a photo album with another, the freshman at Houghton High School reminisced about her first trip to Reynosa, Mexico, where dear friends she has made live among garbage pits and poverty. Maria is still amazed that just five years ago, she was a little girl traveling to the large country where it all started as a family vacation.