That's 2 status holders and 2 guests. so in principle you have to select your favourite pair of cost centres. If one of the little travellers is near 2 years old then that can go fast track. If this is part of the half term rush then you can imagine they will be fairly strict on the rules. So your other option is to see if you can travel in Club or First. That said, Fast Track T3 isn't amazingly faster than normal security in my experience, and can be worse.