^just curious zjw - why do you mention starting up again? [non-judgmental voice]
The original question - do you attend meetings? I ask bc I am in AA and my sponsor also has a 10 yr old daughter. My sponsor will be 3 yrs sober in Oct and she has involved her daughter since very early in her sobriety; her daughter has been to meetings with her. I also see children at meetings sometimes (babies are clueless, obviously, but the 4,5, 8, etc...they are learning). If you are working a program, maybe it is not a bad idea at all to find ways to include her, appropriate to her age and interest in learning and all those developmental things. Perhaps Adult Children of Alcoholics or other resources could help with starting this.
Sounds like you are aware of the need to talk and share with her. Personally, I would want guidance on how best to do this as y'all go along - I imagine you have anxiety over what to tell her and whether you'll be helping her or not!!
Staying aware - for all of us and I would think particularly those with children- and HONEST are ... critical.
Good luck.