I am stunned to say the least, but wanted to add my two cents.
I sort of believe this is already beyond you and [name]SIL[/name]; this has already changed a lot for your family (DH, [name]BIL[/name], [name]SIL[/name], Grandparents, [name]Clementine[/name]'s one and two and now poor [name]Isabella[/name] is being drug in!) This falls under the category of “Family Planing” and I think it’s time to involve the family. Not to gang up on her, but to give her no leverage as I can only think of one way this needs to end.
Now, let’s say you all try with all your might to get her to see the light of day and she fails to, were I you, and NB, I want your opinion on my opinion-
Start calling her [name]Clementine[/name] [name]Clem[/name], or [name]Joy[/name]. Yes, I’ve said it, and I stand by it! When little [name]Isabelle[/name] shows up call her [name]Isa[/name], or [name]Izzy[/name] ect.
This is only if all reasoning fails, and I would enlist the help of your [name]MIL[/name] and FIL and well as your hubby and daughters.
If she ([name]SIL[/name]) tries to correct you just say, “I think it suits her.” With everyone going by this “I think it suits her” philosophy she can’t fight it. If she tries to retaliate by switching your [name]Emma[/name]'s nn, everyone can agree that “She really is an [name]Emma[/name].”
So NB, am I crueler than the [name]SIL[/name] or could I have solved the problem, if the problem doesn’t resolve itself freely?
Blessings,
[name]Bella[/name] <3 (no, I’m not making fun of you, [name]Bella[/name] is my nn)