Nananina, I am really surprised by how unsupportive you appear to be! IMO, it is not unreasonable to expect a baby of 6 months to sleep longer than as described and if the baby has yet to sleep a full night, then she is clearly exhausted and looking for some friendly guidence. Biddy1902, has come to look for advice, not critisism!
Anyway Biddy, you have probably tried everything, but here are a few things that may help:
At 6 months,baby's should probably be encouraged to sleep a bit more during the day, as sleep tends to breed sleep. Could you bring his morning sleep to earlier? At this age my lo was sleeping 9-10am and then 12.30-2.30pm, then in bed by 7pm.
Is he on solids yet? Is he getting enough protein in his diet?
Is he is a sleeping bag (i.e. not waking because he is too cold/hot?
Have you blacked out every inch of daylight in his room (if they catch a glimpse of a toy etc, it can be enough to fully waken them!)?
Do you still dreamfeed at 10pm?
Are you sure there is no noise waking him? I play white noise into my LO's bedroom (and currently have a fan in there instead!) which really helps block out traffic noise!
I think your strategy of not speaking etc is excellent as your LO is learning to distinguish between playtime with Mummy and nighttime=sleep!
I will stop waffling, but perhaps if you give us an idea of his routine, they may be something that stands out that you can tweak?
p.s. one thing I will say in agreement with Nana, is that it always does get better!