@simon_brooke Two things spring to mind:

She had a degree in chemistry and so actually understood a reasonable amount of the science behind global warming, CFCs, and so on. She drove some of the environmental legislation that later Tory governments tried so hard to destroy. Wikipedia has a decent summary, but I suspect acid rain would be much more of a problem now without her work. The Environmental Protection Act that she passed in 1990 has been amended but remains on the books. She pushed to Montreal Protocol, which limited CFCs and helped the ozone layer recover.

More personally to me, her government funded the programme that developed the BBC Micro. The BBC produced a load of teaching material for people to learn to program. Importantly, the government placed (shockingly sensible) sets of restrictions on what schools could buy with this money. In particular, the computers had to come with a programming environment that supported structured programming. Sophie Wilson’s BBC BASIC was one of the few things that qualified. This drove a lot of the UK tech sector’s big expansion in the ‘80s. It’s also the reason I learned to program, so it had long-term beneficial consequences for me, at least. Without at, Arm probably wouldn’t have existed, nor would a number of British tech companies that rode the wave of people leaving school able to program.

Not enough to offset all of the awful things she did.