I understand her anxiety but it makes me sad that she still won't see me should I say anything
With all due respect, I don't think you do understand.
I have GAD (nothing do with covid - officially diagnosed years ago) and when I'm at my worst the rational things you've put in your OP would mean absolutely nothing to me, you can't think clearly the way most people do when you're deep in that anxiety.
To most people all the reasons you've written make sense, yes the chances are extremely low of her catching covid from you, so to you it makes sense that she should be okay meeting even for a walk outside - but she can't see it that way, she can't see (just example numbers) the 95% chance she won't catch it from you, she can only see the 5% chance that she will. The anxiety is debilitating. I don't have health anxiety and covid isn't something that I'm anxious about, however, from speaking of personal experience from other things. The panic that most likely comes over her when you suggest going a walk or meeting up will consume her, she probably isn't physically able to make that step.
Anxiety is something that you can never fully understand without having experienced it yourself. It's not the same as a Normal level of worry/anxiety that most people feel. Even though you're trying to be helpful, saying things like you're tested twice a week and haven't been in contact with anyone etc, is probably having the opposite effect on her. I know myself that when people say things like that trying to help, all it does is make me feel worse as I feel like it should be no big deal and there is something really wrong with me that I can't think the same way others can and I can't see that it's no problem. It just makes me worry about what other people think of me.
Also her DH having anxiety aswell doesn't mean that she should be okay because he is, it affects people differently.
I'm not meaning anything against you OP and I can completely understand why you are sad about it but the best thing you can do is just be there to listen. She'll let you know when she's ready, but she needs to get there in her own time. Can you FaceTime/call for now? I know it's not the same but try not push her and be there for when she feels able, but let her tell you when that is.