Good question. I know for myself I was in the habit of turning away from my inner child and disconnecting, (so maybe that's the opposite problem) but only because of believing the toxic, abusive messages about my younger self. When I did start to connect it wasn't voluntary (and it happened like someone flipped a switch)--totally overwhelming. For me, it was all about learning to view that younger me from a more accurate perspective and not just through the lens forced on me. I think as people who faced neglect and abuse as kids it can be easy to grow up thinking something must be wrong with us, otherwise we would have been treated better and gotten what we needed. Changing the inner narrative is a big undertaking for sure, but doing that combined with comforting or grounding activities helps a lot.
That said, I find that sometimes being "age appropriate" and doing something positive "with" her is the best thing. Someone above mentioned coloring, that's good. For me it's art projects, going on a nature walk and collecting things, eating "kid food" or candy, listening to music or watching movies from that time period, going on the swings at the park (when nobody else is there, don't wanna get stared at), build Legos, climb trees, whatever seems comforting or fun. Yesterday I saved my first snowball of the season the freezer. It's important for me to follow her lead without judgement. Something I notice in healing is there is a lot of emphasis on acknowledging pain and accepting where we're at, and it's totally important don't get me wrong, but there has to be something positive too or else it's too easy to get overwhelmed or discouraged.