We had the luxury of a SAHM, but when DW first started homeschooling, she discovered that the whole "school day" only lasted about three hours, and much of that time was spent with DD working independently. In that context, homeschooling while working full time, especially with help, is very doable.

What took TONS of time was curriculum development, because my DW didn't find one she liked, so she insisted on doing that herself.