Luke,
I am glad you asked on behalf of your friend. There are no 100% guarantees about what speakers, or even other delegates, will say; but it is highly likely that your friend will have a positive and encouraging experience at NWMC. In general there is an open and welcoming atmosphere. Although we have a Presbyterian relationship and Presbyterians predominate, our ultimate allegiance is simply to our Lord and Savior. Our purpose is to encourage believers to participate in what God is doing in the world. Your friend may have individuals ask her questions about her beliefs, and she may ask questions about her own beliefs; but that is always a good thing for all of us to be pushed a little to think about what we believe and why we believe it. Your friend should not worry about attempts to "convert" her to Presbyterianism. Yes, Catholics and Presbyterians do have some different beliefs, but we share far more in common.
Continue to encourage your friend to come to NWMC. A Roman Catholic friend of mine has been on staff the past two years. She has been greatly blessed by the conference and she has been a blessing to many.
Don Dawson, Director