Advice please!!

Hi! I am a 24 year old single mom to a 5 year old baby girl. Her father was not ready to be a father & he left when she was around 8 months old. She is an extremely happy, smart, funny girl. Every once in a while she asks about her real dad. I don't know what to tell her :( I keep telling her she has enough people in her life who love her & not to worry. Today she asked Siri where her real dad lived. Now, before she asked that, she asked Siri where mermaids lived so I think she was just thinking about living situations so decided to ask. She is not sad at all, she never says anything about her real dad out of anger or sadness, & she does not dwell on it. She changes the subject almost immediately. Can anyone offer any advice? Should I be saying something else? Please help! I value all of your opinions & comments ❤️ thank you xoxo