Here is the full list of all 36 Warhammer 40,000: Battle Sister achievements.
You dropped into a hostile environment and found friends along the way (Complete Chapter 3)
I bet you said "My faith is my shield" in your head didn't you (Block 20 bullets with Melee Weapons)
You are worthy of the Emperor's arsenal! (Get 50 headshots)
Kill 100 enemies
Kill 10 enemies with melee
You survived the sanctuary attack (Complete Chapter 2)
30 rounds of righteous devastation (Get 20 kills with the Bolter)
Get 10 one shot headshots in a row
You've fought your way through the trenches (Complete Chapter 1)
You held off the Chaos forces and escaped to meet the Inquisitor (Complete Chapter 4)
You assaulted "The Inexorable Reason" and entered the depths of its madness (Complete Chapter 6)
You've survived the onslaught of the Chaos ship (Complete Chapter 7)
You pushed across the shattered plains of a dead planet (Complete Chapter 9)
You found the Orb (Complete Chapter 10)
A tomb world gone (Complete Chapter 11)
Defeat the Brass Scorpion
Defeat the Chaos Knight
You've found your sister but under heavy circumstances
You've uncovered the Necron threat living under your nose (Kill a Necron)
Slay one of the most deadly warriors of Chaos
Slay two spawns of Chaos
You are a truly battle hardened Sororitas (Complete every level in any order without dying)
You've helped satiate the Golden Throne. (Kill 1000 enemies)
Kill 25 enemies with Grenade Launchers, Barrels and Grenades
Who doesn't love a good explosion? (Kill 4 enemies with one explosive blast)
The frail fall at your feet after a slight gust of wind (Kill 3 enemies with the Faith Push)
Time stops for no one... but you can slow it to a crawl. (Perform Slow Time 5 times)
Kill 6 enemies within a single Time Slow
Block 100 bullets in total with Aegis Shield
Block 15 bullets within a single Aegis Shield activation
Kill 6 enemies within a single Aegis Shield activation
The enemy kept rolling 6's, rules are rules (Die 10 times)
Kill an enemy by throwing a melee weapon
Kill 20 enemies with each weapon of the Holy Trinity (Bolter, Melta and Flamer)
Public enemy No.1 of anything armoured (Get 20 kills with the Melta)
When man discovered fire, they soon figured out how to throw it (Get 20 kills with the Flamer)