Walls and Ceilings - knocking down that dust-collecting heavy texture

i think my mother might have that hoarding syndrome. she just accumulates stuff and won't part with anything. we lost my dad a few years ago and it seems to be getting worse. he did most of the upkeep around the house. so she's going away for a week next month and I thought I'd try to freshen up a pretty gross half-bath on the first floor while she's gone. i'm going to take out some unnecessary shelves loaded with old combs, brushes, towels and other odds and ends that haven't seen use in years. I'm going to put up wainscoating and baseboard, update the fixtures and put up a fresh coat of paint. my question is about the paint. the bathroom has that real heavy texture finish. it might be called popcorn. it seems to catch a lot of dust, which is VERY BAD in my mother's place. how tough is it to knock that stuff down and smooth things over, and what's the best method? It's a small bathroom, and I'll only have to do the top half of the walls since wainscoating will cover the bottom. But I have to make sure I get this project done in the weekend I can head up there. My hope is if she sees one room decluttered and made over, she'll be inspired to let me get at other parts of the house when I visit in the spring and summer. Don't mean to go Dr. Phil on the DIY website, but I wanted to explain the circumstances on why I'm trying to get this done quickly. Thanks for any tips.

Popcorn is only used on ceilings.
I assume this being a bath room that the texture has been painted which makes it tougher to remove. If you can scrape off some of the texture you can mist the rest with water and have a fighting chance at removal. This may be more work than you want to take on - after you remove the texture the ceiling needs to be repaired and either skim coated or retextured - then primed before painting.

Using a good latex enamel will help to keep the room clean.

You might want to hang on to the items you remove for a week or 2 just incase ;)

i'll try scraping some of the stuff on the lower part of the wall just to see how it goes. that area will be covered over anyhow. if it's too tough to remove, i'll just clean the walls the best I can and hit with some good paint. either way, it'll look better. and don't worry. nothing will be discarded. it'll all get boxed, labeled and put in the basement, even the old combs, or dear old mom would throw a tizzy.