All of the races in the Lakeland Trails series are excellent - I've done them all a number of times and am back in again this year.
Hawkshead is one of the tougher ones but certainly within your compass as a 1:50 half runner - history suggests that I'm a few minutes quicker than you over the half and I get round this in about 90 minutes. You should have plenty of margin to the race cutoff but, if you feel intimidated by that, enter the Challenge instead - this is the same route on the same day for the same 'reward' at the same price but with an earlier start so that the marshalls can get home sooner. All the information you need is here
The running surface is good throughout and there is nothing that could be described as technical terrain - although a couple of the descents do require a bit of attention and a pair of trail shoes, if you don't already have any, are a sensible investment. There's basically three inclines of note - the first is long but not particularly steep and begins soon after the start so it can be tough to find a line among all the other runners. The second climb is just after the water station outside the pub at Near Sawrey (about 6/7k I think) - again, not very steep but goes on a while so can be draining - it's not uncommon to see folk walking towards the top. The final climb is the infamous 'Coffin Trail' starting at about 11k - again there's a water station at the bottom - this one is shorter but steeper and reduces all but the very quick people to a walk.
My advice to anybody thinking about any of these events is to enter and to bring the family - there is usually stuff to entertain kids around the start/finish area (the bouncy castles can't operate if its wet), plenty to eat and drink, retail stands and always a friendly and relaxed atmosphere. This particular one is also less than half a mile from Hawkshead village which is one of the prettier locations in the Lake District.