I had to change a male cat's name once. We were told he was a female and we named him "Bethany." He was answering to it when we found out he was a male, so we started calling him "Benny." He didn't seem to notice the difference. Eventually, it ended up getting lengthened out to Benjamin and he always knew who he was. I'd suggest thinking of something that sounds like her name now and change it gradually. Go-ee could eventually become Zoe.