9006 error code when updating Iphone 5s

Today I tried to update my Mom's IPhone 5S via Itunes. I also have a 5S and I updated my phone last week, also via Itunes on my laptop, and it took about 20 minutes to download the update and it installed with no problem. When I clicked on the "update" in Itunes for my Mom's phone using her laptop, it indicated it would take about 90 minutes! I waited patiently while it downloaded the update and with about 4 minutes left to go, I got the 9006 error code message. Since I didn't have another 2 hours to spare, I disconnected and figured I'd try it another day. After looking up about the 9006 error I don't believe it is a conflict with her Microsoft Security Essentials software as I had disabled it prior to connecting to Itunes. Should I try the hardwired approach from laptop to modem and see if that helps? Her laptop, on a normal basis, is a wireless connection to the modem. If this fails - is it possible to connect her phone to MY laptop and try to update it in my Itunes? Can I set up a 2nd phone in Itunes or will this cause problems for me in the future when I need to update my own Iphone? I also saw reference made to deleting the ipsw file that I'm assuming is on her laptop. I guess if the download isn't successful, than this file while be sitting on her laptop and could cause a problem when I go to try it again?? Any suggestions would be greatly appreciated.