Our Gemeinde booked us in straight away for the fingerprinting when we lodged the registration papers - did you register in Zurich ?
It should be pretty quick - but I'd go back to the Gemeinde and tell them that she will be travelling and what should you do about it ?
There might be a back-log of appointments, or someone might have missed the appointment, or maybe they just aren't in a hurry...
Did they issue you a temporary paper ? They can do that on request - it costs a small amount of money - I'd go back to the Gemeinde and ask (politely, don't stress, we find the Gemeinde extremely helpful !).... I'm sure it's easily solved...