Good question, Karen. Are there any other details you could give us, MommaBear?
I think Johnny is a great name, personally. I think it would fit well with Daisy and Vinnie.
I don't know how well Wednesday fits, though. It's just so much more unusual. I wouldn't want baby #3 to feel like the odd one out, you know?
It looks like a long-E sound is the preferred ending, so that's what I focused on that when I brainstormed for suggestions:
Girls: Annie, Elizabeth/Lizzie, Margaret/Maggie, Lucy, Cecily, Constance/Connie, Phoebe, Abigail/Abbie, Mary, Sophie
Boys: Henry, Tobias/Toby, William/Billy/Willy, Frederick/Freddy, Eli (not quite the same sound, but close), Thomas/Tommy, Samuel/Sammy, Westley