Is the marriage of the questioner Islamically valid, given the revelation of facts and information about the husband that she was unaware of before the completion of the marriage, her desire not to separate to preserve her children, and the existence of a problem with the husband's family?

If the marriage fulfills its conditions and pillars, then it is valid, and some flaws in the husband do not affect it unless they prevent the validity of the marriage, such as disbelief.

The wife is not obliged to visit her husband's family or maintain ties with them if they are not her blood relatives, especially if she is harmed by interacting with them. The husband has no right to force her to do so.

A wife's kindness to her husband's family and her overlooking their mistakes are part of perfecting kindness to the husband and noble character. It is preferable to maintain ties with them if possible, without harm.

It is obligatory to treat the husband with kindness and strive to reform him by encouraging him to attend circles of knowledge and associate with righteous people, and cooperating with him in acts of obedience, along with being a good wife, seeking Allah's help, and frequently supplicating.

One must beware of despair and the wiles of Satan, for Allah will not abandon the one who is steadfast in obedience to Allah and is patient. Allah Almighty says: {Indeed, he who fears Allah and is patient, then indeed, Allah does not allow to be lost the reward of those who do good.}