Are you considering this woman as a potential marriage partner? Or do you just want to help her clarify the status of her previous marriage for her peace of mind?
If you are thinking of marrying her, please read this:
1 Corinthians 7
39 A woman is bound by the law as long as her husband liveth; but if her husband die, she is at liberty: let her marry to whom she will; only in the Lord. 40 But more blessed shall she be, if she so remain [a widow], according to my counsel; and I think that I also have the spirit of God.
No need to answer anything I say below. I am just suggesting food for thought.If you and she have no interest in the procreation and rearing of children (she is almost 60 years old), why do you want to get "married?" To have a friend to do things with? You don't have to be "married" for that.
Have you considered that her existing children (if she has any) may not want a new man in their mother's life? A step-parent complicates things in families. A mother that was previously dedicated to her children/grandchildren is now distracted from those activities by a new man who is not the natural parent of those children/grandchildren. This can create problems.
If your purpose is to remedy concupiscence, have you considered other ways of dealing with that problem, such as increasing prayer and penance to receive the grace to be free from slavery to those desires? You say she has trauma from a previous sɛҳuąƖ experience. Does she really need to get back into that kind of thing? Will this always be sore spot in the relationship?
By courting this woman, you are encouraging her to move from a "more blessed" condition (widowhood), according to St. Paul, into a less blessed condition. Yes, what St. Paul says is "of counsel," not of the law. But have you carefully considered his words?
God's ways are not our ways. Always try to conform to His counsels, if possible. May God bless you in your effort.