If you feel like the child you observed would benefit from more at-home support, your research question will focus on how at-home supports can aide in the development of literacy and language skills. If the child you observed would benefit from more play-based literacy activities, your research question or statement can focus on the important role of play in literacy.
Some other examples are:
• How will knowing how toddlers communicate help the reader in their work with toddlers?
• How can one teacher learn from another who consistently sets up a quality literacy environment for children?
• Why should a teacher know how agencies promote literacy development in the home?