I have actually read a lot of fanfiction. I like this because it does not actually break canon. They really never explained where and when Voldemort befriended Nagini. If I remember correctly, Dumbledore guessed that he had met her in the forests of Albania while he was in exile. However, it is possible that Voldemort used Peter Pettigrew to perform any magic necessary to summon her. We first met Nagini after Peter helped Voldemort return to a rudimentary body... he had been in his service for a while at that point. Well done. :-)
Thank you! I tried to leave it open ended because I wanted some flexibility to play with the timing of Nagini and Voldemort's meeting. I was originally thinking that they did meet while he was in exile but did Voldemort really have the strength to make her a horcrux? We know that he got to Quirrel in this time and that Nagini is independently powerful so it is possible. Maybe it's the romantic in me but I also like the idea of Nagini and Voldy having a long standing relationship based on mutual respect rather than need. Something inside of me wants to sympathize with Voldemort and him having a wholesome relationship with Nagini makes that more possible. So much more so if Nagini knew him while he was powerful and found him again in despite his weakened state. I need to do some more research to stay true to JK but will be posting a part 2 soon. Thanks for taking the time to respond!