Taking this question at face value, there are several ways to go with this.
One way is to actually grow out the plants, see what characteristics they have, and then name the line accordingly. No point in calling it "White Blueberry gum" if it isn't white, or doesn't smell/taste like blueberry!
Another way is to just pull any random name our of your "hat" and call it that. Unfortunately, I think a lot of "breeders" do more or less this very thing.
Personally I'd just call it "Eods Blueberry Gum x White Widow F1". Admittedly, that's not the most "sexy" or creative name, but it is the most accurate. If you label it that, not only will you know what the cross actually was years later (assuming you have the labelled ceeds), but nobody will be confused by that.
If you want an abbreviated hybrid name, "White Blueberry Gum" would do.