Actually, Elizabeth is quite impossible for her to die first, because in the beginning of Sister Location, Hand Unit literally confirmed that Circus Baby's Pizza World opens after Freddy's closes. Either Fredbear's, which we know closes because of the bite, or Freddy's, which we know closes with the MCI that happened in 1985. Also, if you take a look at how complex Circus Baby is compared to Fredbear, it's quite impossible, if you consider the fact that that thing had to come before Fredbear's. Also, we know that Elizabeth had to have died around 1985, and we know the crying child died in 1983. The main reason why is because that the MC had to happen first for Freddy's to close, and then the original animatronics, endoskeletons get melted and make the fun times, so either 1985 or 1986 are the possible years for Elizabeth's death.