Of course the other question here is who threw the lemons at your characters in the first place (other than you as author of course!). What was the motivation behind another character causing significant problems? Does your character's main trait help them get out of a situation or make it worse?
My rebellious fairy godmother, Eileen, is stubborn, brave, honest and honourable. This does not make her popular with certain other characters because they know she can't be corrupted (well not easily anyway). But it also means that situations Eileen finds herself in are worse than they might be because she is such a stubborn soul. (It's one reason why I love writing about her, she can almost create her own dramas (!) and I would like to try and get her into some short stories at some point).
Of course characters, like lemons, can become sour. What triggers that? Could it be prevented but the character chose not to (and if so, why did they act like that?).