Cinderella, I would like to say that from personal experience, what has worked have been people who clicked with me personally, who just gave me the information straight, without judging me or checking on how much I was absorbing. Also, they modeled the behavior and attitudes they wanted me to have. They may or may not have been aware of how much any of them influenced me. I will tell you that while every Rabbi I had the privilege of learning from taught me and modeled many things for me, not everything sunk in, but many things did, and I am eternally grateful.
To me, it is like a giant jigsaw puzzle, and you have a chance to give someone pieces to that puzzle. I would say just say to be extra careful not to expect rapid change or even change you are aware of, and to give over the information as it is, and be friendly, welcoming, and there for them, even if they seem difficult. Let them be them, but give them the proper Jewish perspective on any and all topics without making them feel what they are doing now is wrong. They want to please and do the right thing.
Its almost like putting a variety of foods on the table and they will pick and take what they want. It is a lot of work to do that, but you are aiding in building a neshama. And, yes, there will be backsliding and times they seem to be going backwards.
Also, dont get overwhelmed. There is too much for you to teach. A great man who I learned with (he was over 90 years old) saw I was getting overwhelmed since learning one thing led to another and on and on, and it was difficult for me to apply things even though I bought into them in concept/hashkafah.
To help me with that he said to me the following: “You are walking down a road and you come across the biggest treasure chest you have ever seen. It is loaded with diamonds, gold, rubies, emeralds… That is what Judaims is. And it is all for you. And while you cannot take all the contents with you, you should know it is always there for you to go to and take something with you, as much as you like, and as often as you like.” That is the metaphor he gave me about coming close to Torah Judaism. And I still consider myself growing; sometimes faster than at other times.
In short, as long as you are a vehicle for teaching over the information, no matter who the person is, know something will stick, and it is in your merit.
Hatzlacha