I wanted my father to be at home laughing with Ma on Saturday afternoons, instead of with Mrs. Masciotte. (1.38)
This is kind of jealousy by proxy. Dolores wants her mom and dad to be at home happy together, instead of her dad giving so much attention to his employer.
I hated Petey—fantasized about his flying accidentally out a window or into the electric fan so that his spell over Ma would be broken. (2.11)
Yes, Dolores is even jealous of a bird. A bird!
"[Rita] has an ugly mouth." (5.78)
This is one of Dolores's least charming characteristics. When she feels jealous of someone else, in this case Jack's wife Rita, she says negative things about them to make herself feel better. Stay classy, Delores.
[Ma's] newfound sassiness was all for Jack's benefit. (6.143)
Dolores wouldn't have had a problem if Ma was being sassy to Dad, but she has a problem with her being sassy for Jack because she wants all of Jack's attention to herself.
My mumbling to myself turned into a silent conversation to Dante's picture. "Look out for her," I told him. "I wouldn't trust her farther than I could throw her." (13.95)
Honestly, Dolores could probably throw Kippy pretty far since she's bigger than her and Kippy seems like a precious little flower. But it's pretty extreme that Dolores is jealous that Kippy gets attention from a boy Dolores hasn't even met.
It wasn't that I hated [Kippy], exactly; she just didn't deserve someone as sensitive as Dante. (14.8)
Dolores is jealous of Kippy's relationship with Dante, and she feels she's more deserving of it, but why? Dolores is one of the most insensitive people (at least on the outside) we've ever met.
Dante kept his home phone number on the school blackboard for any student who needed to use it. Girls called, mostly […] They were snippy when they got me instead of him. (21.8)
If Dolores is jealous of Dante's students at this stage, she doesn't show it—perhaps because she still trusts him. The high school girls, however, well, they don't know any emotion other than jealousy.
"You sure aren't like Dante's last girlfriend," [Paula] shouted. "What do you mean?" "Well, I don't know exactly. You just seem more like us—a faculty wife." Which meant frumpy, I guessed. (21.146)
We're not sure if Dolores is jealous of Dante's last girlfriend, with her revealing tops and bodacious figure, or if she's insulting Paula here, or both. Dolores does have a tendency to lash out at others when she's feeling inadequate.
"Watch out for Dante," I said. "He bites." (26.114)
It's hard to tell if Dolores is once again offering unasked-for advice to one of Dante's girlfriends (the last time was to a high school student who had a crush on him) because she's genuinely concerned about the girl, or because she's jealous that Dante has moved on… and she hasn't.
"You've memorized your ex-wife's farewell letter," I said. (27.272)
Is this one little bit of jealousy creeping up toward Thayer? Old habits die hard.