I didn't have a problem with the rhythm as such of the first three lines, though I'm not fond of using non-dialogue tags repeatedly like that -- the first two were fine, but the third as set out I found disruptive. Actually, on reading quickly on my first pass of the stories I didn't cotton on it was Micaela speaking in the third line, nor that she was herself the robot, which caused some temporary confusion. Undoubtedly that was my faulty reading by being too quick and impatient, and I imagine I was the only one to have that exact problem. However, even on a re-read I don't think it's as obvious as it perhaps needs to be because the expectation is it's Mama going to be replying to the priest, so in my view in that instance it would have been better to get Micaela's name in first, eg 'Micaela hugged Mama, careful of fragile flesh and bone. "I don't mind. Goodbye." '
However, as nit-picky point, for me the use of "Mama" also caused some expectations which weren't fulfilled (and again this is likely to be my problem alone, but I thought I'd mention it for what it's worth). Used like that, as a name, unless Micaela has a human sibling who is allowed to stay in the church, the story must be being told in Micaela's very close POV, and I'd really have expected her narration to be in first person. So for me it made it awkward to have Micaela's name written as if she's thinking of herself in the third person, and then the loss of her POV at the end by lurching into the congregation worsened it. I'm not sure how to get around that problem, though -- in a longer story I would have a human sibling watching, but in 75 words, that's pushing it! I did wonder about using the priest's POV, which would tie in with my thoughts about the ending in the next para, but that would lose the sympathetic tone of the opening (unless you made it into two sections with a * between to denote the change).
As for the end, no, I didn't see you were aiming to prove she had a soul, but I'm not convinced the re-write overcomes that either (but I'm not a subtle reader of the 75s, I'm afraid, and I rather only look on the surface for what is actually said, rather than what might be implied). I think I'd have tried to bring in Mama or Father G again, rather than the congregation -- eg Father G hears the ethereal sound and realises he is wrong, which would have produced a double unexpected ending, the fact she has a soul, and that a man of his stripe can acknowledge his mistake. Difficult in 75 words, but do-able, I think.
Overall, I liked the idea, but it wasn't quite there for me as a story, raising questions which couldn't be answered (why are they packing into -- presumably -- the church, notoriously cold as places, why not leave the robot at home if she's not allowed in there, why doesn't Mama go outside and freeze with her, why don't we see Mama weeping? I'm not a subtle reader but I am a questioning one!). More importantly, for me, it wasn't steam-punkish enough with just talk of pipes and wires -- and I know my own entry fell woefully short of that, so I can sympathise -- and my poor reading of it meant I missed the theme here, too. Sorry!