I think the term 'soul mates' স্যুইটস্ them perfectly. They were made for each other! & are just the cutest couple like, ever (: They can communicate without words too!
YES no one else can be with alice than jasper! They are perfect for each other and its like they are one soul অথবা nonsoul in two bodies=D No one can ever replace the united couple, Mary Alice Brandon and Jasper Whitlock!!:)