She worries about him, he isn't her place but she worries all the same.
On the plane bound for New York and home, she tries to watch him surreptitiously through lowered lashes. He doesn't notice, exhaustion dulling his senses, but he's probably the only one on the plane who doesn't. Her feelings for Doctor Zond are largely secret only to Solomon himself.
Mercy is probably what's staying Calvin's tongue from unleashing the thousand and one opinions on the subject. Mercy or, perhaps, the threat of Vincent or Maggie's ire. Something holds him back, this would be too good to resist otherwise.
Maggie and Vincent, she can't imagine them ever saying anything to Solomon about her feelings for him. Maggie wouldn't break the implied confidence, betraying her. She can't see that happening. As for Vincent...she's not so sure about why he says nothing. If it's his idea of implicit approval, she doesn't dare ask. He's never said anything to her and if he wanted to discourage her, she'd know.
Maybe he knows as well as she, she'll never say anything. Juliet's in love but she's not in stupid. This is the very definition of unrequited and so she holds her tongue. Holds her tongue, watching and worrying. He's exhausted, this latest run-in with Dorna cutting too close for anyone's comfort. Stress and worry have dug furrows into his brow, lines her fingers itch to soothe away. He's alone at the heart of this, and it weighs heavy. Vincent does what he can but Juliet knows even he has his boundaries. Lines which he may not cross.
She's not worried about the foundation or its work, Solomon never allows that to suffer. She's worried about him, he's doing this alone. No one to reach for in the night, no one to hold onto when its too much to bear alone. He's on his own in this so she worries and, sometimes, she wishes.
Barring a miracle, it will have to be enough.