If you were stranded on an island (I assume we can't leave via invisible walls or some shenanigans) and you could only take one person with you, who would you pick... but they need to be from the Fairy Tail anime.
I feel the answer is quite obvious. Mirajane Strauss. She's my favorite female Fairy Tail character. She's smart, kind, funny, perfect companion material. Especially since she's been through so much, she's wise beyond her years and knows how to comfort people. But even not counting that. She is a waitress. She's used to serving people. I'm not saying I'd laze around and let her do everything, but she probably wouldn't complain about doing her part of the work. Also I assume she can cook, though that might just be my headcannon. She's also incredibly beautiful, I mean look at the second picture. She's a pin-up model in a world of characters like Lucy, Minerva, Ultear, Cana, Juvia, Erza, Millianna, etc... Though if I had to choose the girl I'm most attracted to... It would be Cana. But back to Mirajane, she's incredibly strong, being one of the few S-Class wizards. Sure she's not Gildarts or Laxus or even Erza... but she's definitely strong enough for just about anything we would run into. She's also an excellent singer, not as good as Lyra, but more soothing than Gajeel for sure. Shoobidooba!
All in all, I feel that Mira would be the best companion, being kind, smart, and not destroying everything, Natsu, Erza, Laxus etc...
Admittedly, I wouldn't want to take her away from her siblings or the guild, because if I did I'm sure they would riot... so if this is some kinda Mira clone... then yeah... Mirajane would be my choice for a companion on an island.