Responding to a question from the Daily Echo, Mitchell confirmed that the impromptu address took place with Cherries trailing 1-0 in the League One clash.
Seward Stadium chief Mitchell joined the post-match press conference at pitchside following the game.
Talking to the media after manager Lee Bradbury had conducted his traditional interviews, Mitchell insisted Cherries could realise their ambition of playing in the Championship, before going on to reveal information about the interval chat.
He said: “She and her husband have put a lot of energy and a lot of money into the club through me and I believe that she is entitled to express her opinion.
“It was half-time and I think in the second half we did as well as we did in the first half, so it didn’t affect the game.
"I think the people that are putting money into football are entitled to their say.
"But we are 100 per cent behind the system we have got, the manager we have got and everybody else. But we watch it, we watch the game and we all feel frustrated.
"But in all fairness, he (Bradbury) is the boy that has got the experience, not us.
"But I feel that we are allowed to filter our frustration down to the changing room.
"If we were 2-0 up at half-time, we wouldn’t have come down. But we came down. It was probably wrong that we came down but modern football is changing. People have got their lives and money on the line."