Hi, Anne —

Your friends are pretty much right. When two baptized non-Catholics marry, the Catholic Church recognizes it as valid and sacramental, and when a Catholic and a baptized non-Catholic Christian marry, with the permission of the local [ordinary|bishop], it is recognized as valid and sacramental, but a Catholic who gets married outside of the church (as in this case) does not validly contract a marriage.

I would not be cavalier about the marriage saying that a divorce would be perfectly acceptable. Certainly an attempt should be made to rectify the marriage situation, including reconciliation and convalidation . . . (bringing it under the laws of the Church so it is recognized).

On the other hand, if it [the marriage] is going down, I would be reluctant to consider getting it convalidated. I would also say that since it is not a valid marriage, they should not exercise their conjugal rights until things are straightened out (as such relations would constitute fornication).

We can't advise you on how to counsel your sister-in-law but these are the relevant facts.

Any baptized Catholic, lapsed, non-practicing or not, unless he has defected from the Church by writing a letter to that effect to his local bishop, must, for validity, marry in the Church (which includes getting permission to marry in a non-Catholic ceremony) to a Catholic or, if not to a Catholic, again, get permission of the bishop.

• Baptized non-Catholic Christians, when they marry each other, are not under the authority of the Church and so do not need proper form (as it is called) to have a valid, sacramental marriage.
• Non-Catholic, non-baptized people can also have a valid marriage without the Church, though it is not sacramental.
  

Eric