Thank you for sharing your dream with us. Please take everything that I share back to the Holy Spirit as He Alone gives the accurate interpretation.
I’m not sure when (recent or period of life) you had this dream but strictly from this dream alone two possible interpretations come to mind:
1) The child represents a business/project/ministry/habit/addiction/self. Reflect on “what” is “6-7 years old” in the context of the options I have presented and that you enjoyed. You are in transition and that “thing” is in regression mode (resorting back to a baby).
2) You need to nurture the “6-7 years old” thing to prevent it from regressing.
You will know which of the two interpretations is accurate but the key is you need to “take a step forward,” (a play-on-words) again depending on what option is accurate.