Conversely, I think it shows great character development that she's apparently changed her tone on evolving cute Pokémon like Clefairy and Alolan Vulpix. I really do appreciate the contrast between her past and present.
On that topic, I'm really starting to think some of us are blowing this whole Clefable out of proportion. Even if little Lillie was presumably upset at the time, one of her "I know you're in there" flashbacks with the Pokémon showed her and Clefable playing together just like before. It's not like Lusamine irreparably ruined their friendship by evolving her Clefairy...
The only thing regarding the Clefable background was that Lusamine had it evolved without Lillie's consent or without her knowledge until after the matter. (It wasn't that Clefairy had the stone shoved down her throat, she tapped that stone willingly and with joy!)
That was what Lillie was upset about. A beef against her mother rather than against Clefable.
Snowy it is a tad different in that the trainer asked and the Vulpix refused initially. Once Snowy refused that was the end of the matter for the episode and Lillie was fine with it.