Relationships are always complicated and you are right - unfortunately sometimes a strong connection just isn't enough. It sounds like you both really care for each other but also both have your own insecurities and challenges to work on. From this post it sounds like she is struggling to commit to a relationship because of her previous bad experiences - and I can definitely understand that if she has been hurt in the past. However it also sounds like she hasn't been able to work through and overcome the fears and insecurities that her previous relationship left.

I think the only thing I can say in advice is that while a connection is a large part both people in the relationship also need to be in a place where they are able to commit and trust the other person. For that both need to look at their own supports and seek out help in managing what is stopping them moving forward. It sounds like she needs to look at support to work through her previous marriage and the scars it has left her with before she will be able to completely move on into a new relationship.