We had the same query - as my daughter opted not to come to the US with me, however as the form said list all children, we actually put her details down. I thought it wasnt necessary but my now husband explained the wording wasnt name children who intend to emigrate with you - it was asking for children to be listed. I presume that question is there for a reason.....perhaps someone else can elabourate?
I have fingers crossed that it wont impact your petition....and good luck.
Woudn't necessaily agree with threatening tone advice... having worked in customer services, I can tell you that I was more inclined to go the "extra mile" for a customer who was polite and willing to try and work with me on a problem. I might be they have a particular policy on this - I would explain to whoever you speak to the reason for wanting this - if they seemed unable to help I would ask to speak to a supervisor.
I too did not have any utility bills to send to USCIS - I did explain on the cover letter why this was the case, if you are able to provide written proof from the utility companies I would send that ( maybe get them to send a letter advising that they do not add names or offer the option to have joint accounts).
Good luck with your journey.