Personally, I recently made an ascended Sister of Battle to try and see if I could get them to be about the same amount of usefulness as a Space Marine. After finding out in one of my other threads that Deathwatch is going to be around the Ascension tier of power, is when I started this experiment. While some might argue that an Adepta Sororitas should not be able to, I thought about taking her along the path of a Death Cult Assassin. Now, this is not saying that I went the way of the normal DCA, more a slightly warped faith into a repenting Sister. That would end up giving the Sister unnatural agility, and if you wanted to do so you could give her best quality synthetic muscle grafts to give her unnatural strength. Which on top of power armor would give them near Space Marine strength. It would probably be harder to get her into the Deathwatch's group like that, but with all the ways you could spin things it can be done.
Even though I put this possibility forward, I ended up creating mine with the Inquisitor ascended career. Which, once 500 extra xp is gained, she would probably get Unnatural Willpower. With a secondary bionic heart, and bionic respiratory system, along with cybernetic senses or auger arrays starts to get near the kinds of implants that the Space Marines have. While I admit it is no where near that of a Space Marine, them having 20 different implants, it does start to get a Sister near that of a Marine's abilities. An Inquisitorial Sister would have a lot more reason to be around the Deathwatch squad, though you might have to spin it in a certain way for a longer confrontation, it is quite possible to do so.
I personally put my Sister in Best Quality Light Power armor, with bionic arms and locomotion. So, she might not be the size of the Space Marines, but I kind of see that as a bit of a good thing. I gave her a Crusader's Suppression Shield with the locks of the Arbite model to hold her Ryza-Pattern Storm Bolter, with a bolt pistol set into the other top corner of the shield using the MIU Weapons Interface.
So, just to make it readily apparent. I'm not saying, "This is the only way you can do it" or "Here's how you can" I am just saying that this is how I could see it being done.


