thiswillbe weetabix isn't allowed in Bootcamp, whether before, during, or after exercise.
The general aim is between 20-30 carbs per day (unless breastfeeding). Two weetabix is 25 carbs. 
When you say there were nonlow carb options at your mum's, do you mean she'd prepared meals and you didn't want to be rude refusing? Or do you mean she didn't actually have any eggs, meat, fish, vegetables, cheese, or salad available? 
Have a look at the thread in the Bootcamp section for recipe ideas. There are loads of options out there.