The episode "Full of Life" where Loonette befriends a caterpillar and the caterpillar later dies and Granny Garbonzo sings a song about death. Major Bedhead even cries.
Any time Loonette accidentally hurts Molly's feelings (which unfortunately happens from time to time, if not frequently). Examples include:
"Pinch to Grow an Inch": Calling her a pee-wee in comparison to how much Loonette has grown (Although this is justified, because, being a doll, Molly can't grow.)
"Ping Pong Polka": Forgetting to read Molly a story
"Babs in Toyland": Bringing home another doll named Babs, causing Molly to become jealous.
"This Little Piggy": Becoming greedy with her piggy bank (and especially her lucky "looney") and carelessly leaving Molly tangled in her basketball net, as she goes to visit Granny.
"Sticks and Stones": Calling her a clumsy clown, then accidentally upsetting her more when she tries to apologize.
"It's the Thought That Counts": Rebuffing Molly's offers to help her find her "Grand Wazoo McGuffin"
"Button Up": When Molly finds a pair of red, sparkly shoes she wants for Best Foot Forward Day, Loonette rejects the idea, adding that they don't even match her outfit.
Perhaps, the topper of the above examples: in "Time for Molly", Loonette spends most of the episode having a "me-parade" and is COMPLETELY unaware when Molly tries to get her attention. You just want to give the poor doll a big hug.
Molly getting embarrassed over wetting the couch in "Lettuce, Turnip, and Pea".
In "Snug as a Bug", when Loonette compares herself in the blanket to being a caterpillar in a cocoon, she pretends to be a butterfly coming out. This makes Molly worried that Loonette would literally fly away and leave her. Thankfully, Loonette reassures her otherwise and comforts her with a soothing version of the "Hush Little Baby" lullaby.
Let's face it, any time Molly is sad is depressing enough.
In the Thanksgiving Episode, "Feast of Fools", Loonette starts to miss her Auntie Macassar, who is always traveling. She is near tears when she points out the extra plate that Granny Garbanzo put out (which was supposed to symbolize those who couldn't be at the celebration, as well as those clowns who are less fortunate). The solemn tone in Loonette's voice is just genuinely HEARTBREAKING.
Loonette: Auntie Macassar's not here. If she was, she'd be sitting in that place. I really miss her.
Wobbly: We know you miss Auntie Macassar. We do too.
Thankfully, it turns into a Heartwarming Moment, when Auntie Macassar herself makes a surprise appearance (through a package by Major Bedhead). The hug she and Loonette share especially brings out the happy tears; even Loonette almost sounds overwhelmed with emotion.
Loonette's growing concern when Molly gets lost twice in "Lost and Clowned"; especially the second time it happens when she panics big-time.
Loonette: Molly's lost! Oh dear, oh no, poor Molly, lost and gone! Maybe forever! Oh, what if I never find her again? Never EVER again? Oh, Molly!
The song she sings to Molly after she's been found, especially shows how much she cares for her.
The Season 6 finale which marks Alyson Court's last episode as Loonette. While it's treated like a regular episode, Loonette thanking the audience for coming with a last "Toodles" (and telling Molly that she's the coolest) makes it a bit sad.
In "Clownvitations", Loonette is not allowed to join Major Bedhead and Snicklefritz's club. She is utterly dejected after this, and even sings a sad song about how she's uninvited.
Brief, but Loonette’s worry over Molly being lost under all the trash in the garden in “Scrub A Dub” is quite heartstring-tugging.
about how she's uninvited.