Hello Emma, well done on the pacey session.
However.... !!!!! 8.48, 8.49, 8.34 is considerably faster than the recommended pace. Your current half mara pace is about 9.14 per mile and the range is 9 to 9.15 so don't worry about it feeling tough right now. The goal pace (as in, once you've done some consistent weeks of focused training) is 8.40 per mile but you are not meant to be able to do that right from the off.
I think this raises a good point for everyone, actually. There's no need to run sessions faster than suggested, just because you can - whether it's an easy run or a tempo run or interval session. When you think about it, 'half marathon pace' shouldn't feel TOO hard, otherwise how would you be able to do it for 13.1 miles?
Only if sessions feel ridiculously easy might you think about upping your pace, but at the same time you'd probably be wanting to adjust your ultimate goal, too.