While not much is known about Beatrix's personal life prior to becoming a Rancher, it is made clear through StarMail that she has a special someone back on Earth named Casey who goes into some detail about their interactions via StarMail received during the course of the game.
It is mentioned that Beatrix once owned a shop, which is where Casey adopted their cactus from. The context of the StarMail suggests that the shop had been closed for some time.
Two StarMails, "A death hike" and "New Year's Eve" suggest she has an outdoorsy personality. In "A death hike", they mention she was "serious about the whole outdoors thing" and was "decked out in a pack and gear" and after 5 miles into the hike she wasn't out of breath; suggesting she also has a fit physique to go with it.
In "New Year's Eve", they mention she talked to them about one of her trips to Africa, which is gone into some more detail in "Re: Africa".
All of Beatrix's abilities are granted to her by her vacpack. She is capable of storing up to four seperate items in her vacpack and shooting them out at will. She has the ability to sprint for short bursts which consumes the vacpack's energy reserves. She also has access to a flashlight, a radar pointing directly to the Ranch House - or the entrance teleporter if in The Glass Desert - and she has access to a map of her surroundings.
The vacpack can be upgraded to include a jetpack so she can fly for short periods of time, as well as a water tank so she can fight back more effectively against Tarr. The vacpack can also be upgraded to provide more Health, Energy, storage capacity, and have Energy efficiency upgrades for both the jetpack and sprinting. Later on in the game, Treasure Crackers can also be purchased to open Treasure Pods.
- 1.0.0 - Beatrix is now viewable on the title screen and in her house. Hello, Beatrix!
- Casey's and Hobson's story was finished.
- 0.5.1 - You will now receive occasional starmails from Casey, someone important to Beatrix whom she left behind back on Earth. While there is plenty to read in this update, both Casey and Hobson’s story will be completed in a future update.
- The first syllable of Beatrix's name, the abdomen-like vacpack attachment on her back, and the default color scheme of the vacpack may all be a reference to the honey bee. Her career as a rancher may allude to worker bees, specifically. The addition of programmable Drones references the relationship between a queen bee and her hive.
- In one of Casey's Letters to Beatrix, it is revealed that Beatrix slept in a pod sent by the 7Zee Corporation for a year prior to her arrival at the Far, Far Range.
- Based on this fact and the ending credits song, we can infer that at the time the game takes place, humans have achieved FTL travel 1000x the speed of light.
- She had different looks in earlier versions. In the Prototype of the game, the Vacpack was a Team Fortress 2 Medigun. Up to 0.2.0 releasing, an early Vacpack was released with a textureless hand.
- Beatrix's mouth is a face shader with negative depth values, so that it appears 2D from almost any angle, or "fake 2D".