Welcome to the forum Truthseeker!
It can be very difficult explaining the difference between Methodism and Orthodoxy to parents. First, you don't want to come across as arrogant or condescending towards your mother or her adherence to Methodism. It is also difficult determining what differences are important to highlight when talking to our parents about these things. Sometimes it can be harmful if we begin to expound upon differences when we ourselves don't fully comprehend them. It can also be harmful if we go too far and begin making "mountains out of mole hills" in regards to certain differences. If your mother is the patient sort, I'd recommend that you wait to explain the differences until you are able to contact a priest. That way you are more knowledgeable about the Faith and also because he can help you problem solve these sorts of things. Actually, more likely than not, he would be willing to meet with you and your mother to help dispel any misunderstandings and to try to explain the Faith to her in the most appropriate way.
And really, to this day, I don't even know what the distinguishing marks of my previous faith (Nazarene) are. I'm not terribly smart and have difficulty following extremely complicated theological discussions. So I never had that kind of discussion with my parents. The way I did it was that I started practicing the Faith as I was instructed to during my catechumenate (the classes one take to learn about the Faith before being baptized/christmated). Naturally, my parents began asking questions and I answered them as they were asked. If I had a reasonably good answer I gave it. If I didn’t, I’d admit it and agree to seek one out. Initially, I experienced a lot of resistance from my parents because it was unknown. However, we were able to have respectful and meaningful conversations and they quickly accepted it, even though they did and continue to have some reservations. Now they mention how proud they are of me and boast about me being a good Christian to their friends.
Of course I say all of this without knowing you and so I am relying entirely upon my own experience with my family and making several assumptions about you and your family. Early on I decided that I didn't want to be confrontational with my parents. I saw many Orthodox converts who were "zealous" for the Faith and ended up ruining relationships with friends, parents, relatives, etc. Not only that, but they made Orthodoxy look bad in the eyes of their loved ones, which is a terrible sin. They were prideful, triumphalist, and just downright offensive in the way they presented Orthodoxy.
I say all of this because I want to express the importance of presenting the Faith with love and joy in your heart. It is so easy, at least it was/is for me, to want to rely on my base nature (pride, anger, contempt, cruelty, harshness, etc.) when explaining the Faith, something which is all too common in “Internet Orthodoxy”. I have to remind myself that if my actions lead someone away from Orthodoxy, I will be liable for that on the Last Day. What greater sin is there than to lead someone away from Christ? Tread lightly, which I’m sure you will.
Anyway, I wish you well in your search for Christ in His Holy Orthodox Church. In the Church you will find unimaginable depth, meaning, love, and joy if you look for it. I pray that you find it.
P.S. Please forgive me for any false assumptions I made.