Mrs winder can be pruned. Not now. Spring. Some hebes, some clones of the same variety, can respond well to pruning hard but others sulk and take bit longer. You could lightly use shears but secateura are best but make sure you don't cut too far into old wood. Christopher Lloyd once spoke of cutting this hebe....one thrived the other died. Me? I would lightly shear in spring but take cuttings now. Good 3" to 4", edge of pot, added perlite, cover with polythene and Into warm greenhouse/window sill. These "small" hebes are best pruned each year when young, I think. Or, if you are in colder area.take cuttings in spring before you shear it.