I think you could for sure have a
Diana Catherine, I feel like my brain has already decided that is a fact! Maybe because I love patterns and because you're named after two princesses, having a daughter also named for two princesses makes perfect sense to complete the pattern.
Lavinia is a name I've loved for a long time though and I will always encourage its use!
I love your
Henry Jasper combo so I'd pick that for the boy. It's such a sweet gentle name.
Diana Catherine Henry JasperLavinia Rose
Beautiful!