He mentioned her during a speech at the University of North Carolina.
“She has gone home,” he said, before telling crowds her loss was “hard to talk about”.
The funeral of Daniel Inouye

Daniel Inouye was a Hawaiian US senator for 49 years, between 1963 and 2012.
After Inouye’s d3ath, Barack Obama’s career had been inspired by the Asian/American politician because he was born in Hawaii.
“The way he commanded the respect of an entire nation, I think it hinted to me what might be possible in my own life,” Obama said in 2012.
The introduction of new g*n laws in the US

Barack Obama shared about the victims of the Sandy Hook massacre as he introduced new g*n laws in America in January 2016: “Every time I think about those kids, it gets me mad,”
In 2015 he told BBC that his failure to pass “common sense g*n laws” in the US was the significant frustration of his presidency.
The Aretha Franklin moment

When it mentions surprise guests, it doesn’t get much bigger than the queen of soul herself, Aretha Franklin.
Barack and Michelle Obama were guests at a tribute to songwriter Carole King in Washington in 2015 when Aretha performed (You Make Me Feel Like) A Natural Woman.
The video of the moment, televised by CBS, attracted viewed millions of time on YouTube.