She probably is kind of crazy, depressed, confused, all that. Funny/weird about the snacks for you. Oh, yeah, that'll make up for filing for D!
Do I think it's worth saying? If you feel you have to for some reason. Do I think it will help? No. She's obviously thought about this, been to a lawyer, filed paperwork,etc. She KNOWS how you feel.
I do think your dad is right about the L. You need to have a good L to protect yourself and your family. But, I wouldn't decide right now your strategy. I think it's too soon. You could try to rush it through; or you can have an L that will move slowly and putter & give you time (mine seems to work naturally like that!), or maybe a middle course between the two. Your L should do what you wish. But I don't think you should make that decision now. Enough to just find a good L, talk to friends, talk to L friends, etc.
I've heard many people recommend, easier said than done I know, but try to treat the D process as just a business transaction, don't get into R or D talks, say you'll let the Ls handle it. I think that's good for the R and the kids for you to try to have a level of detachment about it.