What should I bring my host family in Costa Rica?

They live on a small farm. There is a mother who is 38, and we are considering bringing her an apron from Anthropologie, which are about 38 dollars, and very nice. The husband is a driver, and he is 45, I don't know what to bring him. There is an 18 year old boy, and again, I don't know what to bring him. There is a 12 year old girl, should i bring her something like nail polish, or slippers( cute girly ones)? And last, there is an 8 year old girl, and I am thinking to get her something similar to what I get the 12 year old. And last, I am thinking to get them a family gift of linens or towels. My mom lived in a foreign country, and was poor when she was young, so she thinks towels would be nice. It is most likely that the family is very poor, so I will NOT be bringing candy or coffee, or gift baskets, I would like to bring something nice and useful. Also, I'm a girl and 14, if it makes a difference. thank you
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8 year old = barbie doll; 12 year old = make up & girly things; 18year old = find out which sports he likes, in example, soccer, buy him a soccer jersey or a Lakers jersey if he likes basketball; husband = polo shirt; mother = summer dress. the kids would also appreciate name brand shirts and such. the 18 year old boy will also like Nike branded shoes.
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