Adepta Sororitas infantry

A unit of Celestians (left) and basic Battle Sister squad (right), both led by a Canoness.
Adepta Sororitas are an all-female monastic order of the Ecclesiarchy (the church of the Imperium of Man). Their most known department is their military wing, the Orders Militant aka Sisters of Battle - since the Ecclesiarchy is prohibited from having "men under arms" after an inside conflict.
Typically Sororitas' effectiveness is between Imperial Guard and Space Marines: their basic soldiers are equipped similar to Space Marines (bolter as a basic weapon, power armor that allows carrying heavy weapons) and they are more numerous, but they aren't superhumans like Marines. Moreover they lack heavy vehicles (only IFVs and Exorcist MRLS) and by most part long-ranged anti-armor weapons. They usually prefer thermal weapons - flamers and meltas.
While Dawn Of War portrays Celestians as special/heavy weapon teams (2 meltaguns, 2 multimeltas), they are not, these roles are played by Dominions and Retributors. Celestians are more like Sternguard Veterans in actual tabletop.
As about their penal units, Sisters Repentina, they're better left unmentioned. Trust me.