LSR how slow is slow?

having done my first 10k event in 54:34 , modest time i think for first effort, i want to a HM in june , i am still running regularly x4 per week  one is my long slow run 

i say long as i have just started training for the longer distance so my long run was 13k , today i did 9 miles , just under 15k by 400 m, if i will run the longer way round my street to make it 15 another time lol 

i was running at a jogging pace, i could probably talk , but was running with my dog and shes not much of a talker , i wasn't really out of breath , just comfortable effort 

it took me 1:45 at this pace, which i have worked out to be 11.5 mile per hour pace or there abouts 

does this seem the right aim/pace for long slow runs , next week i will go a bit further , my spaniel certainly can cope trotting about at that pace 

with my shorter runs i am doing around 5k , should i be doing further now , i have no 'official' plan of training i mix about days around work shifts and kids needs 

any advice appreciated