My girlfriend (24F) asked me (26M) to be a guardian of our dog in case anything happens to her

So, I have been dating my girlfriend for 5 years and we recently adopted a dog (a 3-year old german shepherd dog) from a local shelter in mid-December 2022. She has a condition called Chiari malformation (a condition where the brain falls out of the skull) and has been diagnosed with it since she was 11, but was only operated on in 2019, but she has pretty much made a full recovery two years later. We have been living together for a year, and she recently asked me to promise that I will take care of our dog in case she has an accident and dies. I, of course, promised her, but she then wanted to write a legal document that I would be the legal guardian for our dog Luna should she die. I, of course, agreed. We wrote it all down, but our friends have been warning us that this will not hold up in court, and if I want to make sure I get custody of Luna, we need to get a lawyer to sign off on the paperwork.<br><br>My question is: How do we do this? Should I call up a lawyer and ask them about it? Do we need to go to court to do it? I really want to make sure I can get custody of Luna, but we cannot afford a legal battle, and generally have savings of about $10,000 together, although my girlfriend makes a fair amount of money, and I make about enough to cover the combined living expenses.<br><br>**TL;DR:** Girlfriend asked me to be a legal guardian of our dog if she were to die, what should we do to make sure the paperwork is legal?