Hi, and welcome.
Deaths are registered where they took place, so if her death is on Scotlands People rather than in the England and Wales GRO index, that means she died in Scotland. The entry on SP will give a county or town, but deaths in the last 50 years can't be viewed online. Instead you have to order a paper copy, either with the link provided or direct from the local registrar.
A death certificate will tell you exactly where and when she died, but not where she was buried (or cremated), so you'd still need to look for clues elsewhere. Newspaper death notices or online obituaries are useful, as well as sites like Findagrave or Billion Graves. I think people sometimes get help from friendly funeral directors too - you'd probably need to try a few in the area where she died.
If none of those help, think about where she is likely to have been buried or cremated. These days, churchyard burials tend to be restricted to less populated areas where there's less pressure on space. Everywhere else it's likely to be a cemetery or crematorium run by the local authority or a private company. Some of these have online records (some of which are at Deceased Online), but in many cases you need to contact them directly. Usually it would be one near where the person died, but with family connections elsewhere it might not be.
If you'd like to give us more information about your aunt (eg name, where she died, roughly where her family might be in England), there are plenty here who'd be happy to try and find where she was buried, though I appreciate you might like to try on your own first.
