sometimes people CAN'T connect with other people, and that's what adds depth to their character. If her being able to connect with other characters seems to be how she is, you can build on her loneliness, and how she copes with that, feeling isolated xyz, to add depth to her character. and whether her interactions with the other characters help her to develop or not, the situations she's thrown into should at least help you to see more and more what she's really like.
Example: Mrs. Moon in my novel "Damsel in the Red Dress" is a static character. she doesn't change who she is through out the entire story. She's powerful, lovey-dovey to a fault, and more. But though this doesn't change, you get to see this one character from more and more angles as the story progresses, that shows the flaws and complexities of the character.
So possibly, getting to see your MC through the eyes of the other team mates at first, then her boyfriend, and then her own, can help readers gradually come to understand the character more, sort of 'pseudo-character-development' even if it doesn't seem likely that she'll change.