I say dive without her.
a). If she isn't having fun diving, then it is a tremendous waste of money for her to go diving.
b). If she isn't having fun, the odds are you're not having fun - which is even more of a tremendous waste of money for her to go diving.
I know of some many people who get their SO to do something that they really don't want to do - badgering them to death. I don't get it. I'm not saying this is you - I'm just talking about in general. I know one couple - wife always wants to go out, husband just wants to stay home. Once wife was badgering him to go to the symphony - he finally said, "OK, fine, I'll go, but I'll bring a book to read". I think she finally got the idea to leave him the hell alone.
Now - I realize that sometimes you need to do things to make your spouse happy - simply "for them". But I don't think diving should be something in that category. I dunno about any facts, but it seems to me that if one doesn't want to dive, and one isn't having fun when diving, that just increases the odds for something unpleasant to happen.
It is OK and normal for a married couple to have different hobbies. If necessary, I think diving should be one of them.
I also agree with the comments about, essentially, let her come to you with something to say about it, rather than you going to her.
I "got" my wife to take a 2-dive DSD course in Hawaii. She never would have done it had I not asked her to. I said that I didn't expect her to ever dive in our cold water (Alaska), and knew she wouldn't like that, but she much really like warm water. I just said, well, give it a try, and if you don't like it, then you don't like it, but at least you will have tried it and know for certain. She agreed. After the first boat dive, she said she was scared the whole time, didn't like it, and didn't want to make the second dive. I said sweetie, that's fine, you tried it you didn't like it, I don't want you to do anything you don't want to do. You don't need to make the second dive. No pressure at all.
By the time the surface interval was over, she decided all on her own that she wanted to try the second dive. So, she did, and she had a good time. Two years later - she decided to get certified, in warm water. So, we went to Florida and she had a 3-day quickie class. By the end of the class, she said she liked diving, felt a lot more comfortable, primarily because now she has a much better idea of how the equipment works. She ALSO said that she would try diving in Alaska. I was shocked.
So, a year after that, she decided all on her own that she would get drysuit certified. A couple of months ago, she completed the drysuit cert and AOW classes and made 6 dives up here. Now she is a certified cold water diver with 6 cold water dives. However, she did it all on her own, with no pressure or prodding from me.