B2 - was asked to come back 3 months later for interview, but failed to appear

[b2_tourist_visa_need_help]

My mother went for B2 visa interview in Aug 2012 but because of an unfortunate incidence, she was asked to come back after 3 month (a specific date in Nov 2012 was mentioned in her 221(g) blue form. No additional docs were asked for).
She failed to go on the specified date (in November). When i check the status of application, it shows 'administrative processing'.
Now we want to apply for her B2 visa again (or get her a interview appointment on the old application itself. I called up the call center and they have asked me to drop them an email with this info (i have done that and am awaiting reply).
Does anyone have idea if i can go ahead and create new application while the old one is still open?

[b2_tourist_visa_need_help]

posting resolution for my own query:
I sent an email to the ustraveldocs email address with this query. Also I did couple of follow ups on their call center number. It took 3 weeks, but i finally got the response that she can walk in any working day at 10.30am.
She did so yesterday. She carried the printout the email we got from ustravelodocs and she was allowed to enter and attend interview. And yes - her visa was also approved