Should i pay more attention to her when in a group situation

you see i have been spending time with this girl and we have hung out just me and her and in a group with her family and some friends but it seems like when its just me and her we can talk and have fun but in a group she just gets quiet and observes me and it like i gotta start the convo and it better be good this is only a vibe that i get from her but i need to know how to keep her intrigued and wanting to enjoy herself with me when we are around other people any advice