I would advise you to NOT go to her church. She is “getting” something there that maybe she needs, but you don’t have to be drawn into it.
If you can pin her down, sometimes the episodes of “Journey Home” on EWTN address how certain people find their way into or back into the Catholic Church.
In the meantime, if she goes for it, you could ask her what her objections to the Catholic Church are, and then work on them, one by one.
In 1 Peter it says:
3:13 * Now who is going to harm you if you are enthusiastic for what is good?
3:14 But even if you should suffer because of righteousness, blessed are you. Do not be afraid or terrified with fear of them,
3:15 but sanctify Christ as Lord in your hearts. Always be ready to give an explanation to anyone who asks you for a reason for your hope,
3:16 but do it with gentleness and reverence, keeping your conscience clear, so that, when you are maligned, those who defame your good conduct in Christ may themselves be put to shame.
3:17 For it is better to suffer for doing good, if that be the will of God, than for doing evil.
(NAB)
So…with gentleness and reverence, you might try to tunnel down on her misconceptions of the Catholic Church. e.g. Who said that? Where does it say that? You know, try to get her to defend her misconception, to the point where you may be able to show her that she is wrong. If you can do this once every three months, you may be able to win her back eventually.
I know a popular priest whose sister left the church for some other strange group. You just never can tell where this sort of thing is going to happen.