Sentria

If it's dust allergies and the apartment is furnished check the upholstery for tears. When I was in a similar situation I borrowed a Kirby Sentria and cleaned the entire bedroom. Vaccumed all 6 sides of the mattress. When I discovered a tear along the edge of the mattress I sealed it up with duct tape. After a final once-over with the Kirby my allergies didn't come back.

Buy a used Kirby vacuum on FB marketplace. Go for a Heritage 2 or later G series Kirby vacuum and you'll be quite satisfied. With the G series, Sentria, or Avalir models, you can find a lot of attatchments for them. They made the same basic vacuum and attatchemts for 30+ years so they are interchangeable. You can still get parts for all of them. The Heritage 2 and older ones are great vacuums but parts and attatchments for them aren't as easy to find. They're still out there though on ebay a lot. Any vacuum store is more likely to carry parts for the newer ones. These Kirby vacuums are a bit heavy and bulky but they have so many uses and last forever. I have one from the 1950s that still works great! You can't buy a better vacuum for longevity. 

Definitely not an impossible request to find something superb on a budget, especially when you are talking about used Kirby models which can be found on Facebook Marketplace or similar types of sites. Sometimes people are selling the units for a low as $10 for older models, which are still excellent, but something like a Heritage II or newer you can find with all the attachments for $100 (I would look for a Sentria or Sentria II which is from this century); new models are like $1600 and people get rid of them on the cheep because they are bulky and not trendy like a Dyson or Seebo but they are absolute workhorses and will outlive you (I have a 1952, 1975 and 1987 model than runs flawlessly along with my recently factory rebuilt Sentria II that I bought from new). If you are a DIY person, repairs are easy to do and parts are cheap and plentiful. When it comes to carpet cleaning, Kirby is tough to beat; They are heavy and bulky but models that are newer than a G3 have a transmission that make it featherlight to push. You can also buy attachments new or used and the vac becomes a canister vac, a carpet shampooer, an inflator, and more. You could return that Hoover and buy a much better overall vacuum in the Kirby and save your self some money ( if you are still in the return period).

Your mom has good taste 😁 Clearly I'm a Kirby fan given the 5 that I own, but if you or anyone else reading this is looking at a used Kirby and worried about smell, make sure you wash the outer bag, change the disposable bag, and replace the old beater brush and wash out the head nozel. Once those things are washed, take a couple of cotton balls soaked with some essential oils and throw them in the outer bag which will eliminate any lingering odors.

Definitely not an impossible request to find something superb on a budget, especially when you are talking about used Kirby models which can be found on Facebook Marketplace or similar types of sites. Sometimes people are selling the units for a low as $10 for older models, which are still excellent, but something like a Heritage II or newer you can find with all the attachments for $100 (I would look for a Sentria or Sentria II which is from this century); new models are like $1600 and people get rid of them on the cheep because they are bulky and not trendy like a Dyson or Seebo but they are absolute workhorses and will outlive you (I have a 1952, 1975 and 1987 model than runs flawlessly along with my recently factory rebuilt Sentria II that I bought from new). If you are a DIY person, repairs are easy to do and parts are cheap and plentiful. When it comes to carpet cleaning, Kirby is tough to beat; They are heavy and bulky but models that are newer than a G3 have a transmission that make it featherlight to push. You can also buy attachments new or used and the vac becomes a canister vac, a carpet shampooer, an inflator, and more. You could return that Hoover and buy a much better overall vacuum in the Kirby and save your self some money ( if you are still in the return period).

Your Kirby will last through the apocalypse.

Find a used Kirby Sentria. We’ve been using ours for 15 years. It’s a beast of a machine

They definitely aren’t the most nimble machines. But they’re great at what they do and add in the benefits of the 1000 adding run by the propeller. I do get what you’re saying for sure. We use robots and run the Kirby weekly for corners.