I would say with 95% certainty that it will have splash coloration, but I am not as certain how it came about.
You can get lavender from lav + blue assuming the blue has a single copy of the lavender gene. But I don't believe you can get it from lav + splash since a splash is a double blue ---...
Mauve is a sex linked trait. Splash + Chocolate = Mauve females and blue males.
I'd say what you have there is likely the lav Roo + mauve hen which will result in a type of splash. I can't think of another combination that wouldn't result in a solid lavender chick or something else more...