It sounds like you have an office like mine, my coworker came with the light bulbs, and although I do not have it as bad as what seems like you do she does seem to be "in every one's business" because that used to be acceptable. Once upon a time in the workforce when you had superiors, what they said was law. And some still tend to work this way, for whatever reason.
On occasion I have to back them down and tell them what's legal and what's not as far as DOL is concerned.
Nasty comments and failure to evolve for employees into todays workforce is one of the reasons I am in the process of switching careers.
I went to my employer and asked him to help with the cost of accounting courses b/c our controller is 72 (yes 72) AND my co worker is 71 both almost out the door (sweet people but still) and I hate accounting but would be willing to go to classes to get educated enough to do the work. His response:
"We don't do that for the people Up Front"
The only people up front are two females - me and my co worker (the only two in the company).
Everyone else works in the field - and the company pays for them to go to either plumbing school or sheet metal school to get certified.
When things like what you are going through are happening, if they are not willing to change the circumstances, you have to. If you have the means to change and go elsewhere, keep it under your hat and take the leap. It sounds to me like you are trying to move walls in a concrete building.
And paying for it in the mean time.
Company party - company funded.
My boss even tried to get me to go do personal errands for him, then he saw I was putting it down for reimbursement, he stopped doing that real quick.
Your foot needs to be heavier than theirs. Put it down and stand your ground.