For starters maintenance isn't included with benefits calculations and hasn't been for a good few years now. So if that's your basis for thinking she was claiming fraudulently you're plain wrong!
Secondly her finances are none of your damn business anyway!
"Basically before DSS started school, DH paid a large amount of maintenance" really?! Enough to cover 50% of ALL costs pertaining to dss?
"as it became apparent that not all the money was going to DSS" which aren't always "obvious" costs! I suspect you mean visible things like clothes, shoes but that child also has to be housed, fed, washed, heated, their clothes washed, provided with appropriate and necessary furniture, equipment, toys, books, entertainment...
Yea right!
"she then met a partner and moved in with them DH reduced the payments (still above CM level)" the legally required amount is a MINIMUM it's a guideline only. And pretty shit to be honest. Your DH's ex's new partner has NO financial responsibility to dss legally or morally so to reduce the maintenance on that basis is also shitty.
If you DID report her it wouldn't just affect her it would affect dss too - nice!
Her benefits would be stopped pretty much automatically while "investigations" took place and it's murder to get them reinstated especially now.
Why would you want to do that to dss?! To anyone actually.
"I think what OP means is she hasn't told authorities "she's living over the brush"!" If so OP can't possibly know this for definite, but that's certainly not how I understood the op.
"Maintenance is not counted towards benefits because arsewipes like your OH and meddlers like yourselves think you can dictate how it's spent." Actually it's because when it was being included children were being plunged into poverty because so many nrps wouldn't/didn't pay in full reliably and regularly. I fell under this system for a short while, if my ex paid £5 it was assumed by dwp he would pay the full amount he was meant to and continue to do so and so my benefits were reduced by the amount he was supposed to be paying me penny for penny leaving me seriously short! To the point I was going without food and desperately needed clothes/shoes.
"Ahh yes, ‘full benefit’ that mythical thing invented by people who feel themselves superior to anyone who claims any benefits." Yep!
"But when the money is being spent on drugs, that's ok?" Aye right! You've thrown that grenade in cos you're not getting the answers you wanted!
"Given the brutality of the current benefits system, anyone who grasses anyone else up to the DWP is a worthless piece of shit." Hear hear!!
You just don't want your husbands money going to his son - no more than the legally required minimum anyway.
Yea you sound a lovely stepmum 🤔