I'll try to explain it as I see it...
There would have been many Jews in Paul's time who were zealous and God-fearing and who followed the Mosaic Law as well as was humanly possible because they had been told by the elders that this was the only way to please God, and those faithful Jews sincerely believed the elders spoke for God. Yet, Paul would have told them that righteousness does not come from observing the Law, but from placing faith in the resurrected Jesus as God's chosen Messiah. When teachers in the church began deviating from the apostolic message, they—as well as those who followed after them—were warned to stay true to the word they were given. The writers of the New Testament would not have made the effort or subjected themselves to hardships on behalf of what they taught if it was not important, and if it was not the only way. Obviously what Christians held to was important. On some issues, there was no latitude.
The central issue the orthodox church has always had with JW and most other groups rests on the person of Jesus Christ. The position derived from the canononical writings is that Christ has equal status with the Father. Jesus has sovereign power (Daniel 7:14), all authority (Dan. 7:14 and Matt. 28:18), will be judge of mankind, and is worthy of worship. The Father exalted him to his right hand as Lord over all, and all created things are being brought under his feet. Some scriptures make reference to Christ's inner being having shared the exalted status with the Father prior to his incarnation (John 1:1; Phil. 2:6). That the Father exalted the resurrected Jesus to this supreme position according to his will, and that man was to honor Jesus as he would honor the Father was a pivotal teaching. First, this was testified to by God himself, and if it came from God, it needed to be accepted. Second, it was the basis for accepting the teachings of Jesus—rather than keeping the Mosaic Law—as the will of God. This not only applied to Jews under the Law, but also Gentiles, who would not need to accept the Law as part of their inclusion into the church. Anyone who accords Jesus a lower status, whether it be as an incarnation of a created angel, a spirit brother of Lucifer, or simply a good, moral, miracle-working teacher, is at variance with the expressed will of the Father as given in the Biblical texts. For someone who may not understand about the status of Jesus, but still regards him as supreme living authority to be followed, that is a practical faith that, I would think, meets the requirements.
I wouldn't say what the fate of the woman is. All people in JW, LDS, or any number of other groups are not automatically excluded from Christ any more than all people belonging to orthodox churches are in Christ. This is a matter for the individual heart. Plus, many people who are in these groups are not aware of all the doctrines and their implications. What we can assume is that If this woman is totally committed to JW as the only true representative of God, then she is most likely committed to unconditionally accepting anything that has been laid down by the Governing Body—past, present, and future. Here it is a matter of taking personal responsibility for what we give credence to. We have to take responsibility for our own path. In the case of an organization or group which claims to adhere to the Bible as authoritative, we should examine the Scriptures for ourselves and compare them to claims that have been made. Particularly, in this time, in this culture, with Bibles so readily available and so many in possession of at least a basic education, there is no good excuse not make this comparison. Any group which claims to base its teaching on the Bible but discourages its people from reading it and interpreting it for themselves has to be suspect. These groups seem to consider people to be incompetent. So the mistake comes in blindly accepting someone else's explanation of the Scriptures. (If, upon examination and study, we come to the same conclusions as someone else, at least the position we take will be truly ours—we haven't abrogated this responsibility.) Leaders and teachers of the Word will be held accountable, but that does not relieve individuals of their own responsibility, especially under the circumstances most of us live in today. My personal opinion is that if this woman sincerely wants to do God's will and please God, he will present her with opportunities to see the errors of JW. But we would have to ask if there are other circumstances holding her in the organization. Is she actually held by the fear of the social consequences of questioning JW authority? Is she more afraid of the changes it would mean? What other factors may play into this?
I don't know what hell really is, or if there are different levels. I just know that the Scriptures tell us that what we accept about the person of Christ is not trivial and we are personally accountable for our choice. To say that we allowed someone else to mislead us doesn't appear to hold value. I don't know what kind of allowance God would make.
Because of the sin nature in all of us, we would all be headed for eternal separation from God—it is the default destination. God offers us an opportunity in Christ to escape that fate. The Lake of Fire was prepared for the devil, the beast, and the false prophet. So it's like a political or military alliance: we get whatever the side we line up with gets. If we ally ourselves with the winner, we share in the victory. If we ally ourselves with the loser, we share in the loss.
I think this would be the basis for what that person said about the woman.