DEAR MISS MANNERS: I have been with my boyfriend, “Eli,” for four years. We fell in love during the pandemic and have pulled through many difficult situations together, strengthening our bond. Eli is about to get full custody of his 8-year-old daughter, “Cat.” It’s a very overwhelming process, but so far, we are coming together to support each other at each hurdle. Here’s the caveat: I have only been around Cat a handful of times. While I care about her because she is my love’s daughter, I don’t feel a connection with her at all. I have connected with my former partners’ children through the y…