The news comes from the Twitter feed of one of Lahana's "Haven" co-stars, Eric Balfour. On Thursday (June 19), Balfour explained why Jennifer might not return:
Hey nobody is more bummed about @emmaklahana not wanting 2 return 2 the show than me but she had 2 do what was best 4 her & her family...
— ERIC BALFOUR (@ERICBALFOUR) June 20, 2014
It's a good reason, even if it isn't the happiest news for "Haven" fans.
Lahana joined the cast of "Haven" at the beginning of Season 4 and appeared throughout most of the rest of the episodes. In the Season 4 finale, Jennifer collapsed, seemingly near death, after opening and closing a portal to another world. The news that Lahana probably won't return indicates that Jennifer isn't going to survive her ordeal.