Literacy in the learning community

Hi ladies! So I was looking at the questions for this week and couldn't think of anything that interested me as far as what we talked about last week in class. What DID come to my mind is what I am seeing in my field placement, as far as literacy and the learning community, so I decided to talk about that a little bit.
I have noticed a lot of growth in my students from the beginning of the year till now. But I have also noticed the large gap between those students who are being nurtured and taught at home, as well as in the classroom, and those that are struggling to keep up because they are not getting the support either in school, or at home, that they need to develop these literacy skills. There are three children, two boys (brothers) and a girl, who are above and beyond many of the other children in the classroom as far as reading and writing. The students were working on a worksheet the other day that seemed to be very demanding compared to what they are used to in class. Although they have reading groups with the teacher, there are differences in the levels, of course, of all the children. Many of the kids needed my help or the sub's for that day to finish the worksheet. They were given a word bank at the top of the sheet and had to fill in the words where they went on the page. As I went through I had to ask them all, except these 3 students, if this word was the right one, or this one, or that one. And I noticed after a couple times that my voice was giving away the answer most of the time (I talk in that cheery higher pitched voice when I'm around students and they are doing good at something, I think we're all guilty of that at some point! :) ). These three students sat down, and as soon as I told them what to do they were filling in the words, correctly, and were done before I knew it with the worksheet! I know that the two boys' (twin brothers) mom is the one that subs for my CT all the time and takes the initiative to work with the boys at home and help them read and write, so does the mom and dad of the other girl. How can we as teachers help to further develop the other children in the class so that they can develop these reading and writing skills that the advanced students have, while still challenge and engage the advanced students? These are questions I hope to get answered by the end of the semester, I really don't know if I would be prepared to deal with this sort of situation in my classroom right now as a teacher.