Shirley Chisholm tried for the Democratic nomination in 1972. Perhaps Carter picks her as his 76 running mate she gets the 84 nomination like Mondale did. Then the only issue is how to have her win in 1984.
George Wallace's wife was Governor of Alabama. Maybe shenanigans could happen there.
Have Margaret Chase Smith as somebody's Vice President and have her climb up from there.
Reagan/Smith is a fairly balanced ticket, but Smith is far too old in 1980. Reagan/Smith 68 followed by Smith 76 (if she only serves in January of 1980, that's still a women president in the 80's no?). Reagan considered Ed Brooke as a running mate in 1968 IIRC, so Smith isn't that off as an idea.
Otherwise, how about Ford/Reagan in 1980, Kirkpatrick still being appointed UN Ambassador in 1981, and Jeanne Kirkpatrick ends up Republican nominee in 1984 with Reagan deciding he is too old to run? She picks Jack Kemp as her running mate (thus uniting Foreign Policy and Economic conservatism) or Donald Rumsfeld (a supply sider who was good with Ford and has plenty of cabinet experience) and wins handily.