You need to be aware that if your wife gets involved with JW's again and your child falls seriously ill, your wife will not want them to have a blood transfusion. Even if that means they die. And your wife would also want to die rather than have a transfusion.
The horror of this is highlighted on the front cover of a JW magazine called the Awake:
Below is a article about this issue from an excellent website called JWFacts:
http://www.jwfacts.com/watchtower/blood-transfusions.php
Many times this challenge comes along. JW's who 'drift away' are vulnerable to getting involved as they never research their faiths teachings. Having children seems to encourage some to return. Of course it's impossible to know what your partner will do, but unless they learn the truth about The Truth (The Truth is a phrase JW's use to describe their faith) they may end up getting pulled back in.
Points to ponder.