You're in a tough spot. You want to support her but not condone her actions that clearly go against scripture. I agree with Silverado that you should contact pastor and consult with him. In the Catholic Church, you are not supposed to take part in the Eucharist if you have any sins that are not confessed.
On the other hand, as you know, a lot of people use God and religion to justify to themselves the things they are doing are OK because God understands, he knows my heart. IMO I don't think they are truly seeking God for forgivness and salvation, but as an outlet for their guilt. And that much is true: God alone knows her heart, not you and maybe not even her.
