(( Can I go Envy for Polly? o: ))
(Sure! Three others Polly is jealous of...
This is actually a tough one! Polly doesn't tend to do jealousy.
I think primarily she's jealous of anyone really who had a good relationship with their parents. She didn't, and didn't even know one COULD have a good relationship with their parents until she was caught by her trainer and met other Pokemon. She won't let herself see or know her children now, because she's scared she'll mess up the same way her mom did with her.
Specific others she's jealous of include Basil of askbasilandendive. Basil's relationship with Wyatt is one she watches more closely than Wyatt thinks, and is a constant source of jealousy for her. She misses the kind of relationship she used to have with Wyatt, and seeing someone else he seems so close to makes her a little green.
The third would be Grimmwald the Gengar, from grimmwald. His relationship with his boyfriend, and his semi-child Sammy both make Polly feel jealousy, and also incredibly guilty: Grimm spent forever lost and wandering around looking for his boyfriend when he went away, and Polly has someone she felt that way about right there and she'd never come down off her own high horse to pick it back up, and she never will because however much she wants to, she has principles and she won't break her word to him that it was over when they broke up. She'll be as close a friend as she can to him, but in her mind their time as lovers is over - and Grimm and Audino make her feel immensely jealous.)