I want to marry a revert woman who's family r kuffar and they do not know she is because she would face extreme abuse otherwise. My parents are against me marrying because of age. If we get married without telling either of our parents does this go against not announcing the nikkah.

A Muslim woman’s wali cannot be a non-Muslim, so where she has no Muslim wali, a Muslim judge or the head of the Islamic centre marries her. The scholars differ on keeping it hidden: the Permanent Committee held that the presence of two witnesses counts as announcing it and the contract is valid, while Imam Ibn Baz said announcing the nikah is obligatory. A man does not need his parents’ permission to marry, as Imam Ibn Baz said, though consulting them is better. Also if people will know that they are married like friends and others except for parents then this is announcing as well.