Jasmine doesn't love anyone other than herself. The reasons she got back with fateh are a bit multidimensional.
1. Her self worth is tied to her 'unmatched beauty'. She believed that she can get anyone get down on their knees in her enchantment. When fateh was with tejo, it hurts that belief. If she wasn't even pretty enough to keep a guy for a few weeks, then her entire existence had no value.
2. This is tied to previous point too, but it deserves separate mention, there's always some sorta competition between siblings (even the best ones, they just know how to deal with it, and keep the positives). Between tejo and chameli, there's never any competition because tejo is just that perfect. Recently we've started to see that hatred openly in Jasmine's behavior. She hates tejo. And now she's getting a chance to get back at her.
She'll leave fateh at the first trouble they encounter. Be it Canada, or a luxurious life... She'll drop him like a hot potato