I think what you have to do with her is make her stick to the Bible for every assertion that she makes. After all, she claims that what she says is "scriptural", right? So ask her to show you the scriptures to back up everything she asserts. For example, where does the Bible say that it is wrong to celebrate a traditional day if the origins are in some sort of pagan worship? "Pagan" is such a buzzword among JW's that they just automatically assume that anything the least bit "pagan" is somehow of the devil and to be avoided completely. But the Bible doesn't make that distinction, except for the Old Testament Israelites actually engaging in worship of gods other than YHWH. By celebrating Christmas, your intent is to worship the God of the Bible, not pagan gods. The mere fact that some of the trappings originated in pagan lands is irrelevant. As the Watchtower of 1972, p.63 said regarding wedding rings,
Really, the question is not so much whether wedding rings were first used by pagans but whether they were originally used as part of false religious practices and still retain such religious significance [emphasis theirs].
Surely no one would argue today that Christmas
still retains its pagan significance; its customs have been adapted to honor Christ.
Next, you might ask her to scripturally support her contentions that celebrating Christmas is the same as worshipping it, and that such 'worshipping' of Christmas is equivalent to worshipping Satan. She will come up dry on both accounts.
As your coup de grace, refer her to Romans 14.
4 Who are you to judge someone else's servant? To his own master he stands or falls. And he will stand, for the Lord is able to make him stand. 5 One man considers one day more sacred than another; another man considers every day alike. Each one should be fully convinced in his own mind. 6 He who regards one day as special, does so to the Lord. He who eats meat, eats to the Lord, for he gives thanks to God; and he who abstains, does so to the Lord and gives thanks to God. 7 For none of us lives to himself alone and none of us dies to himself alone. 8 If we live, we live to the Lord; and if we die, we die to the Lord. So, whether we live or die, we belong to the Lord.
So, at this point, she will have only the human reasoning of the Watchtower to bolster her argument, while you will have scripture that
specifically states that what days you celebrate are between you and the Lord. The Watchtower response to this scripture is to say that Paul was talking only about the Jewish feast days, but the scripture does not say that; it merely states a general principle without limiting it. Additionally, those who assert this must then accept that it would be scripturally acceptable for Jehovah's Witnesses today to celebrate the feast of Tabernacles, feast of Trumpets, Passover, Sabbath, etc. if they wished, or even the feast of Dedication (Hanukkah), which was apparently celebrated by Jesus! John 6:22,23 shows that Jesus was at the temple at the time of the celebration. What do you suppose would happen to a JW today who instituted such celebrations in his family?
When dealing with JW's, you need to separate scripture from Watchtower reasoning, which is really just opinion. If you do that very carefully, most of their arguments fall apart rather quickly.
Tom
"The truth was obscure, too profound and too pure; to live it you had to explode." ---Bob Dylan