Our inspector had no problem at all doing a joint inspection at the same time...and we have always had our inspections done this way!
She didnt say anything about needing seperate policies etc, but did ask us what we thought our individual strengths were. Foe example if one of us was better with arts/crafts, or one enjoyed the physical play with the children more than the other etc...but totally understood that as we spend every minute of our childminding day working together that we do things the same way, and that the way we do our risk assessments/observations etc were done the way we jointly chose to do them.
She did say that she needed to make our reports as different as she could, and would use different examples in each of them.
Obviously this was all ok as we were graded outstanding! And we certainly don't have seperate anything!
We did also make it clear to the inspector when she called that we wouldnt accept being inspected individually because of the disruption caused to the children due to missing out on outings to toddler groups, soft play, story times etc.
I hope you get your inspections sorted soon, but i cannot see why the same inspector would want to come out to you twice in a short space of time, when she could do the inspections together and at the same time!
I also think that when childminders work together they should be able to have the one report that reflects their joint practice instead of individual ones!
We would prefer to have one registration number, one certificate of registration to display, one report etc, etc! Would make everything so much easier!