in the last book i dont want to spoil it but bella and edward get married then on their honeymoon on esme island bellas last human wish is to sleep with edward. edward agrees but he wasn't aware of the fact that she can be made pregnant by a vampire. When their baby came out it was a girl called renesme but as soon as bella held nessi she bit bella. If edward didnt turn bella into a vampire she would die, and they had a deal they marry shes a vamp
in the last chapter of the series , after bella's child she will die , but edward want to save her so he turn her into a vampire .
so in the end she will be as a vampire like her lover .