Huffington Post contributor, Lisa Belkin, believes we do:
Let’s ignore for a moment the excellent point that we never seem to feel the need to modify “fathers” with “working” and focus instead on whether it is time to change what we call mothers who do or do not receive a paycheck. Because what we call them simultaneously reflects and alters the way we perceive them.
Read her complete article at: http://www.huffingtonpost.com/2013/03/27/we-need-a-new-word-for-sahm_n_2966251.html 
Is there a name for SAHMs that truly describes the contributions they are making? Do we need to categorize any woman as a SAHM, WAHM or WOHM at all?