How can I connect to internet via wifi without getting close to router to recieve a good connection?

I have a Dell Inspiron 14 laptop, the connection to the Internet cares about 20ft a way out of the computer. My daughter joins a mini-notebook, Acer, that wherever it is located in the house. Can someone please help me? Even if I go in the same room with my mini netbook daugters always good connection, my laptop doesn’t get it.