Sisters by Lynne Cheney
I did find it, and I also found another listing (for the out of print version) with this hilarious customer review, giving it four out of five stars:
A touching tribute to the feminity that is lesbianism, March 25, 2004
Reviewer: Mary Cheney from a secure, undisclosed location
"Being ruggedly masculine myself, I was touched to see that my mother does in fact understand the latent burning desires in every woman to discard the politically correctness of phallic worship and enjoy the tenderness that only another woman can offer. Makes every woman want to come out of the closet and shout! 4 stars!!"