I think she'll only choose one. I mainly think it will be Olivia because she's been able to adapt to Machino's world, so it wouldn't be too difficult for her to stay, plus she has a job. Olivia previously said she can't accept Machino's wish, that she only wants her to have eyes for her. I'm not saying Sophia is a bad option, just that things would be easier if she stayed with Olivia.