There's still multiple ways she can do that and there are cases of females dedicating their lives to a church without celibacy.
It mostly depends on whether she becomes a priest, nun or monk. Priest/monk can still marry and even engage in sexual activities and father/mother kids but only with their spouse. But nun...yeah celibacy and looking at the outfit (which I totally missed, good eye), you're probably right. Truly a waste.
About Wenty's nun dress, the author seems unsure or disorganized because I see her wearing a long sister/nun dress during eating.
And then I see her dressed again in her no-sleeve dress in the last pages.
So maybe he had a different order of pages in mind. But, having seen some raw chapters, it looks like Wenty is going to be in the orphanage/church from now on.
So that seems like a done deal.
About the church, I mean it feels like she is more or less looking for a place where she isn't lonely. So maybe she isn't "marrying God" and more like seeking redemption through taking care of kids (I keep remembering that this is an orphanage not a church, yet I see almost no children).
So yeah, I hope this isn't Wenty's final destination. I hope she finds someone who loves her for the goodness inside her.
Because she was just a child when she did those "sins". Grew up in a house that didn't teach her how to be a good noble. Even God would give that person a second chance.