My 16 year old daughter had her gallbladder and appendix removed 2 weeks ago and she has bllod in her stool after a bowel movement is this normal?

Probably not: Call her doctor that did the surgery and discuss this with him/her.

Unuasual case: This is quite unusual situation. Was it read blood? What was the amount? If it is bright read and significant amount go back to see the surgeon. What a young age to start with abdominal surgeries. I wander what was the indication for surgery: gb and by the way took the appendix too ? I doubt that going after an inflamed appendix and than take the gb would not be a wise decision... My opinion...