By definition a disaster recovery solution needs to be geographically separate. You’re protecting yourself from catastrophe, and some of those scenarios include your main location burning down, flooding, being hit by a tornado, etc etc.
So you either need to collocate systems with a friend who you trust, purchase colocation services from a provider, or use a cloud service to achieve what you’re looking for to truly have a DR solution.
As far as how to do that, the main idea is to have that point in time available on a system that, even if you get compromised, the backups won’t. The old school method here is to use an external hard drive or a tape device, and physically store that offsite. So like use your regular backup mechanism, and in addition to what it’s doing now schedule a daily/weekly/monthly job that backs up to this other device, and then store that away from your main location.
That’s essentially the idea though, and there are any number of solutions you can use to do it.
The best thing you can do is treat her respectfully. Say hello when you pass and be courteous when you talk, but putting up the professional barrier to any kind of personal relationship likely is your best strategy.
Your coworkers also see these traits. They will see you treating this person with respect, but also not participating in her drama. That’s the mentality you should have to forming a winning workplace presence. People will see you treat her kindly, but also do not participate in the drama.
Everyone respects that person