That's kinda what has me lingering a bit. I am waiting to see how things turn out with her husband, not so I can jump into a relationship with her if it goes sour, but I would like to be able to help her like she helped me.

I don't buy this. I think this is how you would like to look at it. If a year from now she contacts you and you help her out she did you. Again you would be having a EA if you are still married. To help her out you would do that again? This is the one aspect where I think there lies a difference in our sitch. If I was to ever reach out to my friend again it would only be if my marriage was over. Not with a hope of making it more. That was not there when he was helping me. We have known each other since I was 11 years old. We have been friends for most of my life even if we do not speak to each other for years we were still friends. And I have that knowledge that if ever in this life time I need him he will be there. Not as a boy friend but as a friend. Now grant you we do have a history of being boyfriend and girlfriend from long ago.
But it did not work. Our friendship did.
So even thought I feel as if I lost my best friend and even if I miss the support I know it is not really gone but there is a barrier made of respect for my H's feelings that I will not cross as long as I am with him.
And unfortunately you can sugar coat it anyway you want as to what your intentions would be as in to help her out. It is just a excuse to keep holding on when what you really need to do is place a simular barrier between you and OW out of respect for your W.

I have no idea if my W seems my emotional self as being manly or not. She has never said one way or the other.

Have you ever asked her how she views you as a person?

Unfortunately, the twins are regressing

That happens exspecially with how close they are in age.
My D went through a stage of wanting to use the potty chair when I was potty training her brother. She was 5. Way past the potty chair age. But did not like the fact her brother had a special potty.