I think I can speak for many Realtors that are involved with Short Sales when I say this must be the number question I get EVERY day. Usually the question starts.. "Can you check on the status of my Short Sale?" or "how much longer do you think it will take?"
Boy if only we had the answers, it would allevaite so much stress and wasted time for everyone involved. The answer to your question is NO ONE KNOWS, not the Listing Agent, not the Selling Agent and usually NOT most of the people involved negotiating the Short Sale. Until you near "the end", there is NO set time frame for a Short Sale, nor will you get many helpful answers.
I have been doing them on a daily basis for about 4 years and all I can tell you is I had one take 2 weeks (absolute miracle) and I am currently involved with my longest one at a year and 2 months. Every Short Sale is different, every lender is different, every negotiator is different, so there isn't a clear cut answer on the length of time it should take.
Banks are overwhelmed, understaffed and some lenders really don't care if the property goes to foreclosure, they actually make more money on most foreclosures in the long run (versus short selling the home).Just because the seller signed your offer, it almost means nothing to be honest, only that the Short Sale process has started.
The lender is the one that is going to make the decision and all your file did, when the owner of the property signed it, was get in line behind thousands of other short sales at any given lender. By the time your file sees human eyes it could easily be 3 - 6 months. Once someone looks at your file all that guarantees is that someone is going to follow up on the file, it does NOT mean they will accept the offer.
Many things can still happen; the bank can reject the offer, the bank can counter your offer (very common now since property values are rising), the bank can accept your offer if the owner of the home makes a "contribution". Nothing says you are guaranteed to get the property so I would have a plan "B" if I were you.
Believe me when I tell you, it is definitely frustrating for you, and extremely frustrating for both agents who are counted on to give "updates" on the status of the Short Sale. Imagine getting a text, an email and/or a call from a dozen or so clients that you have an "accepted" short sale offer for, every day or every few days. It increases our workload, increases everyone's frustrations and wastes a lot of everyone's time.
All you can do at this point is wait, eventually there will be an end in one direction or another. But as I said, have a back-up plan ready because you just never know what the decision will be.
I know that is not what you want to hear, but it is the absolute truth when it comes to short sales, no one has a definitive answer.
Thank you and Good Luck!