I was always told you would stay in the marriage you are in. See if the last marriages were even valid to begin with. Seek annulment and have the marriage you are in validated by the Church.
And be prepared to wait a very long time indeed!
Here's the thing. What you can do in the Catholic Church greatly depends on 3 things:
1. the current status of your former husbands--whether they are living or dead.
2. and if still alive, if they have remarried,
3. and if your first marriage was outside of the Church but has been judged to meet the Catholic standards of a marriage, in order to be considered a valid marriage according to the Catholic Church.
After you wade through all of that, it gets complicated indeed!
if the first marriage was considered to be a valid marriage according to the Catholic Church, (but not inside the Catholic Church) then it stands to reason that the second marriage was not a valid marriage, and would have to be annulled by the Church, before you could proceed to join the Catholic Church, and then that first marriage would have to be "Regularized".
Getting back to the first marriage, if that husband is still living, whether he is remarried or not remarried, then you would be considered as still married to him, but living apart, and thus not eligible to marry again so long as he lives.(and if he was remarried and still living, he would be considered as still married to you, and his second marriage would have to be annulled if he also wanted to join the church.)
If husband #1 is deceased, then we move on to the same considerations for husband number 2.
Under those circumstances, (husband #2 still living, you and he are currently married) you could have the marriage regularized, both be accepted into the Catholic Church and then have access to the sacraments provided that while you go through that process, both of you agreed to remain completely chaste and sleeping separately without congress or physical contact (a Josephite marriage) as though you were both single until the marriage is regularized.
That situation would exist from the time that you applied to be received into the Catholic Church, and while your marriage was going through the process of regularization.
Yes, getting through RCIA is the easier of the two processes.
Now situation #3:
if after you are received into the Catholic Church and if your situation changes yet again (husband dies) and instead of remaining a chaste widow for the remainder of your life you want to marry again, then all previous deals are off.
you revert back to your pre-marriage status, and you may not receive until your previous marriages are vetted and resolved if that was not done before you married. If your previous marriages were vetted, then you remain as a member of the Catholic Church, a recognized widow, and expected to remain chaste until your marriage.
And yes, you get to go through 6 months of pre-marriage training again!
Now, let's say (just to further complicate things) that after you join the church, you find someone that you would like to marry within the Church, and they are already eligible for marriage. That is a bit simpler.
You would still have to go through the examination of your previous marriages, and they would have to be declared null by the Church before you could begin the process of marriage preparation, which takes 6 months to go through.
So, If you can possibly manage it, it's easier by far to come into the Catholic Church as a single unwed person first, and then get married, rather than to reverse the two.
P>S> if you come into the Church through RCIA and you are a widow at that time (your non Catholic husband dies previous to your applying to RCIA) you are unfortunately never going to be recognized as a widow because no matter how long you were married, your marriage was not in a Catholic Church, and you were not a Catholic. Them's the breaks.
