Hi there,
Unfortunately, I think you got the wrong forum. Rest assured gallbladder issues are not a a red flag for ovarian cancer. Here is a link to the gastroenterology forum where you can repost and hopefully find others who have more advice for you:
http://www.medhelp.org/forums/Gastroenterology/show/68
That said, I know over a dozen people who have had gallbladder surgery and stones and it has been cured by surgery. My grandmother was one of them. I know it is scary with your mom facing surgery but this type of surgery is performed often and with a good success rate. I am sure she has been in lots of pain but if she is in the hospital now it sounds like help is on the way! Take care and try not to worry. I will be praying for your mom! :)