A more common sentence that might help you understand better is "My boss takes credit for my work". This means that when people say the work is well done, the boss pretends that he is responsible for it. That is, it is good because of something he did. So this sentence is this example is Frannie saying the positive changes in Paul are all because of her and the things she has done ("her doing").

Just like you, I also watch movies and TV shows with english subs in order to get to understand the plot better. I has halped me a lot since I started. Some shows I watch without the subs to also improve my listenings skills. Keep up your good work!

Thank you. But actually, I'm watch Friends with engsub. I can't hear 100%. This film too much idiom and slang. Sometimes I don't understand why they lauch. But I understand the basic terms. I realize I'm making considerable progress when I watch it.

PS I am impressed that you are able to watch and understand "Friends". Well done !!!