If you value your family, ease up and work slowly to undermine her views in a way that won't threaten her.
Concentrate on finding out why she thinks that the JWs are Jehovah's earthly organization. Also, determine what the consequences she'd suffer if she decided to leave. Would she lose her parents or other extended family? Are all her friends JWs?
Compose a list of questions that bother you and then give them to a non-JW friend. Then, after a little work, arrange to drop by his (or her) home and then let your friend plant some seeds and, if necessary, go back. But know that it's like me and the cat. If my wife had to pick between us, I'd be the one hitting the road! So understand your place in the scheme of things. She's under full mind control mode and none of this will make any sense until she's out from under the spell. And if you pick now to stumble, you may find yourself in one hell of a situation.
As I understand it, she can't divorce you unless you take up with someone else, so you've got a little leverage. You just have to determine the right time to use it. What you've got going for you is that there's nothing in the Bible that indicates the Jehovah's Witnesses are God's organization; there are no angelic ministrations, no visions, no dreams, no spiritual gifts. Jesus didn't issue a press release in 1919 when he inspected the earth's religions and came to the rather remarkable conclusion that the Watchtower Society was the closest religion to what he wanted. If true, this is the first time in world history when God took a less than...proactive...part in setting up a kingdom, or church. In the past, Yahweh has not been very passive when it came to naming prophets, calling apostles, warning the wicked. Whereas the Lord spake unto Jeremiah saying, " Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, and I ordained thee a prophet unto the nations." (Jer. 1:5) He didn't visit the earth and examine everyone who claimed to be a prophet and then choose Jeremiah as being the closest one to what he was looking for. So that's been my major problem with the Watchtower organization. Yahweh didn't instigate the religion, he didn't appear to anyone, didn't send any angels, didn't ordain a soul, never gave them the Keys of the Kingdom, necessary for being able to bind in Heaven or on Earth; never called anyone that we can determine. And yet the law states that in the mouth of two or three witnesses shall every word be established. So even if Russell claimed to be chosen by angels, he's lacking a couple of witnesses and we're not obligated to receive his word only. So what's the draw? Seems to have all the attributes of a manmade religion to me.
Good luck!
"For ye have not chosen me, but I have chosen you and ordained you...."