if a wife has an affair resulting in a pregnancy that she terminates and does not tell the husband, is that admisable in court against her? in the state of FL
It is not admissible. It isn't relevant to anything pertinent to the divorce. Cheating is almost never relevant to a divorce, and since no child was born, there is no issue regarding timeshare or support.
Marginally relevant at best, admissible - probably.