are those evidences enough for her to file a case against us and had the case didn't pursue..what case can i file against her

im having an affair with a married man and this has been going on for four years..although we never lived together,,we continue dating and seeing each other in some places until he got me pregnant but the child's surname is mine and i didn't declare the father's name on my child's birth certificate..he decided to leave his wife and live by himself..i visit him once in a while but i never slept in his place..his wife found out about our relationship and threatens to sue both of us saying she has evidences such as my text messages to his husband and a photo of mine found in his husband's wallet.she also said that she already knew about his husband having a child with me though i denied it to her with all my might but she insisted that it's his husband child and that his husband admitted her the truth though i keep on denying it and that she'll use that too as an evidence...she said that she'll see to it that a case will be filed for both of us and we'll rot in jail..my question is were the evidences the wife had, enough to file a case to both of us and what case would that be?will it prosper in court and what case could she charge against me?thank you