My dear Lacrimel,
I am glad to hear that you have managed to help Lucinda step into a church. We both know that she's overly self-conscious and timid, which is something the Fallen Angels have been working with for a long time, so this bit of progress is a good step forward. However, since her first experience was nerve-wracking and a little unfulfilling to her, the goal is to now keep her attention focused. She wasn't able to find a priest available this time, but a second visit to an actual sermon with other people might help. Of course, the Fallen Angels will try to convince her that she was lucky she wasn't seen the first time and that if she goes there a second and gets spotted, she will be thought of as a practicing Christian and mocked. If she goes during a sermon and sees people that she knows, they will also try to discredit the religion by reminding her of all the things about them that she hates or thinks passing queer.
You must remind her that those people are just like her-sinners in many ways, but seeing that there's a way to cleanse themselves and become better people. Even if all of those people fail, the fact that they are trying is a wonderful thing. Even if you can't always follow your father's orders and rules, the fact that you try and sometimes succeed makes him happy. You must also try to convince her that if she thinks this religion and church are correct, then it doesn't matter whether or not other people mock her. As long as she knows what she believes is right, then what other people think doesn't matter. She hasn't been mocked yet either, so she doesn't know whether or not she will be. I believe Humans say they'll cross that bridge when they get there. This is a very useful phase to try and calm down Lucinda so that she can be a more self-confident person in everything, including her beliefs.
In the meantime, keep encouraging her to read hard scientific texts and Christian texts, even the ones the church doesn't consider to be canon. They are still an interesting read, and if Lucinda shows some interest in them, there's no reason to try and discourage her from it.
Your affectionate Aunt,