She said the campaign's schedule has kept her away from her husband for much of the past month, but as the campaign winds down, with just 5 days left before the election, Thursday marks her last day on the trail alone. 

Mitt and Ann Romney will reunite on Friday, along with GOP vice presidential nominee Paul RyanPaul RyanRyan downplays shutdown threat Poll: Trump voters have positive opinion of president Overnight Regulation: Senators call for 'cost-effective' regs | FCC chief unveils plans to roll back net neutrality MORE and his wife, Jenna — and a slew of other Republicans — at a rally in Ohio. From there, Mitt and Ann Romney will campaign together in Colorado on Saturday and New Hampshire on Monday.

"It's an emotional day for me. I wish I could tell you what I've learned on the road, and what I've heard," she said, referring to the Americans, particuarly women, she has met on the campaign trail.

She was interrupted at one point by a "first lady" chant from the crowd.

Cindy McCain, the wife of 2008's GOP presidential candidate Sen. John McCainJohn McCainTop commander: Don't bet on China reining in North Korea Trudeau, Trump speak for second night about US-Canada trade McCain: China has done ‘nothing’ on North Korea MORE (Ariz.), and Jane Portman, the wife of Sen. Rob PortmanRob PortmanTrump tax plan prompts GOP fears about deficit Overnight Regulation: Senators call for 'cost-effective' regs | FCC chief unveils plans to roll back net neutrality Senators push 'cost-effective' reg reform MORE (R-Ohio), helped introduce Ann Romney. Portman joked that the three of them have been on "the girls' bus driving through Ohio" for the past two days.

"I really like rolling with the girls," Ann Romney joked in her remarks. 

She also urged supporters to donate to the Red Cross in order to support relief efforts following Hurricane Sandy. She suggested donating by text, using the number "90999." 

She then paused and said, "What does that remind you of? Herman Cain! 9-9-9! You can remember that."

Cain, the former CEO of Godfather's Pizza and candidate for the Republican nomination, promoted his tax plan frequently during the GOP primary debates as "9-9-9." His plan would replace the current code with a 9 percent flat tax on all personal income, corporate income and sales. 

Ann Romney said one of her grandchildren, who is three years old, would dance around the room singing "9-9-9" after watching the debates in which Cain touted his tax plan.

"Herman's on to something there," Romney said was her response.