None of these except for the last has a unique answer because the answer depends upon what you want the tag question to ask. For the tag question, there are two possibilities (1) It can ask if the sentence is true or not, or (2) It can ask about the status only of Lily.
In case it is (1) that you want, it may not be possible for the tag question to clearly pose this question. For instance, the meaning of
"Neither you nor Lily goes to the party, don't you?"
is not at all clear. Who is the final "you"? Is it just you, or is it both you and Lily. Nobody can say because in English "you" can be either singular or plural. On the other hand, if it is (2) that you want then the sentence
"Neither you nor Lily goes to the party, doesn't she?"
is also a terrible sentence because it contains a double negative. Nobody can say what it means. Literally, it means "Does she NOT NOT go to the party?" Only a computer can make sense out of that. If I wanted to clarify the status of Lily, I would say
"Neither you nor Lily goes to the party, or does she go?"
Similar considerations apply to the other sentences as well. Only the last one has a clear unique answer: "isn't she".