Modify Append Query to include new table(s)

I have a workbook with ten sheets for user input. The ten sheets are identical in structure. I've created queries, then an append query to tie all of the sheets together and transform to unpivot. Now I need to add an eleventh sheet for user input, but I can't figure out how to modify the append query to include this sheet. The query editor wants to make a new append query using the original and appending the eleventh sheet. However, all of my further manipulation, pivots, etc., are looking at the original append query. What am I missing? This can't be so difficult.