My fiancee also has an active US B1 visa. It hasn't helped so far. Even though she has an extensive travel history.As long as the biometrics are showing, the application is considered complete.
It is taking 5-6 months processing now. We are seeing some people getting approval in a week or 2 as well. Completely random
Do they have any travel history? An active USA visa seems to expedite processing [ I submitted an application for my friend on June 17 and he got PPR today - He does have an Active USA Visa]
There is no way to expedite. Just wait