As Catherine has learned to speak, she has corrected nearly all her early mispronunciations, but one that’s stuck is “lellow” (the colour of a banana). When I finally got round to googling this phenomenon, I found that Neal Whitman wrote quite a bit about it a couple of years ago. Googling also turns up Lellow as Alicia Keys’ nickname. I wonder how long it’ll take Catherine (who’s 4, by the way) to grow out of it? (We’re certainly not going to force her out of it.)
This month we went to Tenby on holiday, and after a couple of days she added a new word to her vocabulary: “Elsh” (the language and people of Wales). Criminally cute, and no sightings on Google.
Update: C is keen on Intrusive L. She says, for example, “Gelloff” for “Get off.”
Dadge 
You wrote: “(We’re certainly not going to force her out of it.)”
My son, at about age 4, put on his “jamamas” to go to bed.
I nearly clocked DH when he corrected him. They grow out of those things so fast.
(Some stick, though–my entire family still calls them “underbrellas,” the way my sister did)