Row height is set in points, and one point is 1/72 of an inch. So, setting a row height of 72 would print out to a meaurable height of one inch. That's the easy part.
The hard part is column width, because that depends on the font size and type you have formatted for that cell. Column width is set by character widths, which by the way is not an option in condional formatting because of this very reason - - CF cannot change the Excel environment and font types would do just that.
You can come close but maybe never get it exactly right for the column width to be one inch. Look at Application.CentimetersToPoints (one point being .035 centimeters) and multiply that by the average of characters for your font.
The following macro is not perfect, using D4 as the target cell, but it comes close. Tweaking it from here might be more trouble than it is worth but it's your call depending on how strong-willed your wife is.
Sub Test1()
With Range("D4")
Dim ColWidth As Integer
ColWidth = 100
.ColumnWidth = 1
Do While Abs(72 - .Width) <= ColWidth
ColWidth = 72 - .Width
.ColumnWidth = .ColumnWidth + 0.1
Loop
.RowHeight = 72
End With
End Sub