Have been running for a year now and regularly run 10 miles for my LSR but am slow, 9.30 min miles on the long runs. But I understand what you're saying so think I will have to give it a miss.
9:30 isn't slow for your LSRs. It sounds patronising, but LSRs should be Long, they should be Run and they should be Slow! A lot of people forget about the "slow" bit. Indeed you might want to slow down a bit more.
As for your question... the vast majority of people in your circumstances can certainly do it, and enjoy it. How to tackle it will depend on your motivation, age, body etc. The HM could be treated as a LSR endurance training run... But unless you want to shave off every possible second for the 10K, then I'd say you should race them both. By May, your LSRs will be beyond 13 miles, so you should be in really good shape for the half. And unless you've some specific circumstances, you should have shaken off 95% of the HM after-effects by the following Friday.
If you do a HM on the Sunday, then suggest do a recovery jog on Monday, rest on Tuesday (reverse those if you prefer), Wednesday, short recovery jog, Thursday, rest. Friday some sort of speed work to get your legs moving again... like a 4 mile run easy run, with 3 or 4 bursts of 10K pace... just for 200m each somewhere in the middle, Saturday rest, then go for it again on the Sunday.
You might lose a minute or maybe two on your 10K time, compared to a scenario where you don't 'race' the HM. But what does it matter? And then again, you actually might benefit. If you know you've to do that HM, you're more likely to focus on endurance training in the next 2-3 months, which is often neglected by people preparing for a 10K.
So... go for it. But be prepared to listen to your body and if you're not quite right after then HM, then pull out of the 10K, or take it easy.
