The 17-year-old Wellingtonian blasted a world high 232 against the hapless Irish in Dublin, then took five for 17 with her leg spin after having a two-minute kip on the physio's table.
It is the third-highest ODI total ever, beaten only by India's Rohit Sharma (264) and Kiwi Martin Guptill's 237 against the West Indies in 2015.
Kerr, who made her ODI debut aged 16, told the Radio Sport Breakfast she was exhausted and exhilarated.
"It's pretty surreal. The day couldn't go any better. I can't really believe what happened," said Kerr, who was unaware of the record situation while she was batting.
"I had throwdowns without a helmet, there was one short one I pulled which I had to watch really hard so my eye was in quite well.
"I didn't get off to a flyer, I had to work hard. But once I got through that it got a bit easier. I'm definitely going to use that bat again. It's pinging off nicely.
"I could hear announcements [about her records] being made over the loudspeakers but I couldn't hear because of all the clapping.
"I am quite tired. I had a wee nap after my innings, before going back on the field. I was a bit sore."
Kerr has previously batted down the order for the national team, but was elevated to opener in Dublin and has long-term aspirations to return there. Her previous highest score was 152 in under-21 cricket.
"I found I was opening a couple of days before the game, which was a bit of a surprise," she said.
"In the future that's where I want to end up (opening). I've grown up in junior cricket as an opener who bowls leg spin. That is something I want to do at the international level. In the future I want to be equal at batting and bowling."
Kerr's parents arrived in Ireland too late to witness their daughter's amazing innings. The White Ferns are about to play England and South Africa in a tri-series.
