I really don't think it will be that bad for her.
As much as the story is about being able to choose what you are and what you do, and how we all have the ability to change, Gems by nature are still born for specific roles, and those roles are always going to be a part of them in some form or another, no matter what other changes and growth they undertake.
Pearl may be free to make her own choices without a master, but she is still the organizer and "mother" of the group, due to her desire to serve as a Pearl. Garnat may be able to love who she wants, and even be a leader, but her core is that of a wise guide (Sapphire) that is also a staunch defender (Ruby). Bismuth is still a builder, Peridot is still a scientist. These are always going to be a core part of them, even if they go off and learn other things like gardening or cartoons. Unlike Steven, they are not kids, there is only so much change they can do.
Spinel, as we saw in the garden, was created to entertain. It's what she lived for, making Pink Diamond smile and keeping her laughing. While I don't think she will ever go back to how she was pre-abandonment, she still wants to make people happy. This is one reasons she didn't feel she could remain on Earth. It's not that she didn't feel Steven wouldn't forgive her, but the baggage of what she did was going to taint any attempt to go back to what she wanted to be, back to a fun-loving goofball.
Of course there is still the chance she makes the Diamonds bored just like PD was, but considering how Spinel herself changes on Earth, I am sure she understands when to pull it back, and may even use her new status as the Diamonds personal little "pink diamond replacement" to go off and make others laugh around Homeworld. She isn't going to rely on one person, or one set of people, ever again.
That is my take on it.