It will always be hard for kids, the first time. You can't rush them, I mean, it isn't possible to tell someone how they "should" feel, it won't stop them feeling that way, that isn't how emotions work. It just teaches them to stop coming to you to tell you how they really feel.
I know you are frustrated as she has only known this chick for 24 hours lol. And it is... sad but, also a part of the process. But we have to remember she isn't use to this, and she is no doubt going through other things in life, especially if she has been isolated at home doing online schooling. It is important she learns to say goodbye and not fester on it. It will get easier with time. A funeral to me isn't an issue if she plans it and talks at it and you explain to her that a funeral means saying goodbye.
I was able to sit the kids down the first time we lost chicks and negotiated how funerals are really for animals you have a connection with, a funeral is a way to honor the bond you have and to say goodbye to a loved animal,a cat or a dog or a loved hen, did they really feel a connect with 7 day old chicks? Just be there for her, check in with her how she is emotionally feeling about "everything" right now, try to talk to her about things she is looking forward to, raising the chicks left? Christmas?
You are doing a good job and she will learn how to regulate her emotions, she is just little and she needs you to remind her about all the good things she has to focus on, she has lots of chicks to care for that are healthy.