I think that love is nothing to be afraid of. As this is so far a relationship without commitments, you both are free to see or stop seeing each other. That doesn't mean that you should have no feeling for each other. Are you happy with her being married? Don't make her take off her wedding ring! Do you like the idea of having a more traditional relationship with her? Talk about the possibility and she may or may not want to really do it.
It is not a sin to want different incompatible things at the same time, actually this site is all about that in many ways, full of couples and people finding answers on what are the boundaries that each other can or can not break and be fine with it.
Now, you also mentioned she is indecisive... if the deal is that she has been teasing you with having a relationship with you, but constantly backs off from acting upon, and that is hurting you, then that's a different thing and you shouldn't rationalize it with a "take a distance to respect her marriage".
So, TL;DR:
1) What would you do in my shoes? Any advice is greatly appreciated.
Decide if you want a relationship or if you like making her hubby a cuckold. Same for the baby thing, think if you really want to be a *******, and if you accept the high risk of being a non custodian parent if she doesn't want to live with you after she has it (you still have to support even if she lives with her husband, according to law). Depending on that be very clear to her on what are your wants or do not wants and if things don't work, that's a part of life.
2) If I do stop seeing her, what do you think she will do? Will she move on?
If you stop seeing her, do it because you don't want to see her, not because you are hurt and want to hurt her so she has to do something. You are 27 years old, so you are young still, but mature enough to realize that manipulation trough withdrawal is a pretty toxic relationship model.
Best of luck!