In short it's hell. Very much depends on your spouse, and my wife is so entrenched, if the society would start baby sacrifices she would still defend them. They did a complete work on her Just yesterday we had a big fight again, because she just can't understand why I don't like the society. I know I'm doing things very wrong, she knows that my oppinion is that she's brainwashed, which is very bad (in all the books and advices I've read it's the single most important thing not to say).
I would not recommend your friend in any case to marry a JW, unless he's very sure that either he will be a loyal JW, or she is not that loyal and there's a really good chance of getting her out. A non-JW married to a loyal JW at best can be bearable, at worst it's hell. It can never be a truly happy marriage. It's better to have loved and lost than to graduately see her being lost to a book publishing company.
Just a couple of examples: we planned going to a theater the other day, and asked her to buy tickets. She refused, because she was with an other JW, and she might get stumbled by her going to theater . On an other occasion when I asked if she wants to see the "Avatar" she said she must first do research to see if it's immoral or violent. Also she said she would never come to some gathering, party, vacation, anything where there are non-JW people (meaning if we would be in a company with them), and by me refusing to believe in the society's lies, obviously I can't go to any JW "party". So that kind of rules out almost any kind of recreation, except a very select few things we can do by ourselves.