All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The husband is not obliged to do anything because he had already come out of the second stage of Ihraam which is finalized by performing the Ifaadhah Tawaaf. As regards the wife, she is obliged to offer a Fidyah (ransom) of either slaughtering a sheep, fasting for three days or feeding six poor people, half a Saa’ (i.e. 1,240 grams of rice or wheat or similar items considered as common food in the country) for each one of them because she did not come out of the second stage of Ihraam which makes it permissible for her to have foreplay (with her husband) according to the view of the majority of the scholars .
However, if she did not know the ruling or that she did so out of forgetfulness, then she is not required to do anything as Allaah Says (what means): {Our Lord! Punish us not if we forget or fall into error.}[Quran 2:286] It is confirmed in a narration reported by Imaam Muslim that Allaah said, “I did (accepted your supplication)”.
Allaah Knows best.