"and wouldn't wanna lose her friendship because of my new faith in Jesus."

Up front on your mind ought to be the very reverse of this line of thinking.... that you can, now, only truly be her friend because of your new faith in Jesus. That now you are an ambassador for Christ... not for yourself or your family's name or anything else... you belong to Christ now and though of course you want to remain her friend, the friendship has to be on completely different bassis now. And as her friend you need to tell her the inevitable end of following the Wiccan religion. I am reminded of (Acts 16:16-18) As we were going to the place of prayer, we were met by a slave girl who had a spirit of divination and brought her owners much gain by fortune-telling. She followed Paul and us, crying out, "These men are servants of the Most High God, who proclaim to you the way of salvation." And this she kept doing for many days. Paul, having become greatly annoyed, turned and said to the spirit, "I command you in the name of Jesus Christ to come out of her." And it came out that very hour."

So here is a girl who was simply "telling the truth"... and in so many pluralistic, New Age type of religions we are told some truth..... but sadly along with some of these truths is the lie that there are many ways to God and salvation.... the witch of Endor may have conjured up Samuel to tell "the truth" to Saul, but this did not make what Saul did "right" even though he was told a truth... this slave girl in Acts 16:16-18 went about telling the truth about who Paul was, but the truth itself did not matter as much as the way the truth is arrived at, this had to have been the reason Paul eventually rebuked her. Why else? So for your Wiccan friend, she may have some things right... be loving and kind to others etc.... and these are good qualities to be sure... but she has arrived at these qualities in exactly the wrong way and needs to be lovingly rebuked that only Jesus is the Way, the Truth and the Life and no man or woman will go to God but through Jesus. Eventually, as you lovingly tell her of her need for Christ..... and its not as if you need to blast her with everything all at once, your friendship allows you a unique inroad to share the truth with her about the exclusivity of Christ over time, with patience, love and kindness, but never sacrificing truth at the expense of any of these other qualities (1 Peter 3:15-16) but in your hearts regard Christ the Lord as holy, always being prepared to make a defense to anyone who asks you for a reason for the hope that is in you; yet do it with gentleness and respect, having a good conscience, so that, when you are slandered, those who revile your good behavior in Christ may be put to shame."
So while the quote from St. Francis of Assisi (Preach the gospel at all times, and if necessary use words) is kind of quaint, its not really fully biblically faithful.... actually our conduct, our works, should be preaching the gospel at all times, but part of that very conduct, in fact, a very important part of that conduct, is being ready always to give a verbal account, is verbally preaching.... ie it is a "defense" of the truth. In Greek the word "defense" is "apologia", namely a verbal defense..... not an "apology" in the modern sense of the word as if you would be going around telling everyone how sorry you are for being a Christian for an "apology" in ancient Greek was an official legal term where one used to say that when they were giving an "apology", a defense of their position, ie a reasoned verbal defense for their actions as in a court of law or in front of your accusers, (see Strongs or Thayers concordances for the word "defense" in 1 Pe 3:15..... see also "Plato's Apology at http://classics.mit.edu/Plato/apology.html for this usage --- namely a verbal reasoned defense so for this reason) and that this task is a command of God to every Christian everywhere... not just the Pastor or the specialist in Apologetics.... just like it is not just the evangelist's job to share the gospel, so too it is every Christian's responsibility to give an account for the hope that is within them (ie engaging in Apologetics), you must do this as you speak to your friend about your faith in Christ, giving a reason for the hope that is within you, and just as going out into all the world making disciples of all nations simply cannot be done without the use of words, of preaching the gospel, of speaking the (biblical) truth into peoples lives, about how much God hates witchcraft etc...... Apologetics is taking the time to study the Bible as to just why it is that witchcraft is sin..... its about knowing and sharing the exclusivity of the Christian Gospel, about how Jesus was not merely just another great moral teacher, why the Bible can be trusted due to the number of manuscripts we have etc etc etc... all hard work to be sure.... but hard work that is commanded by God for each and every Christian.....