How to fire a client?

Hello business team,

I am doing 1:1 coaching and dreaming of moving to group coaching.

Three months ago, I launched an offer for a 3-month group coaching program and one person signed on.
I had another woman who wanted coaching but could not afford it and I invited her for free, so we could have the group experience.
Even though only one person was paying, client A, I wanted to create the group so I could learn from this experience and build the program/record videos while we go.
Client A ended up paying in small payments, and she has now payed 500 of the total 2000.
She made small payments at the beginning. She was getting great results. Both of them got great value and results from the program. When she stopped paying, I lost the motivation to record more videos so I only offered the group coaching sessions.

Client A is sending me huge, long emails every day to ask questions about different challenges. Indeed I said in the coaching package that support is offered, so answering questions. But she is sending really huge emails and it takes me hours to read and respond.

I guess I want to ask: is it ok to tell her that I am stopping the group coaching?

Three months have passed and I offered her the group sessions and a few 1:1.  (Not much in between sessions support which I did say I will offer and more recorded videos/lessons) She paid 500 out of 2000, so I think she got a lot for what she paid and I hate receiving her long emails. I feel like she is draining my energy and even taking advantage.

Is it ok to stop the coaching with her, both?