Here are some ideas I was thinking of doing about, Tinkerbell and Zarina.

Here is one about Zarina, what if when she left after fairy Gary dismiss her from her job as a dust-keeper, she was captured by James and was taken to a wizard or witch and was turn into a human and her wings become tattoo like marks on her back. The witch or wizard and James made a deal, the deal was if James can bring a fairy to he/she to test something that can turn a fairy into a human. For James and his crew, they was promised something that will let their ship fly. ( It your choice if it a magic 💎 or a brooch ) when the exchange was done, the Witch or Wizard went back to their home and place Zarina who is tied up and have water on her wings so she can't fly on a table. Zarina scared ask what going to happen to her ? The Witch or Wizard tells her that she was going to be a test subject on turning a fairy into a human, Zarina stares in disbelief and tries to escape but fails, then the witch or Wizard gets a strange flower, ( it can also be a potion that is pour on her, or a strange dust like pixie dust and blow it on her ) when it was finished Zarina was human and unconscious. The Witch or Wizard have someone carry her to a room to rest. ( I will let you decide what will happen, will Tinkerbell and her friends find her ? Will fairy Gary explain and apologise to her ? )

Another idea

When Zarina ran away she was captured by an evil pirate witch who used magic for her own needs, she also got something that can open a portal that let her travel out of Neverland, the pirate which has been working on an experiment that can turn a fairy into human size. One day a sailor or a noble man, who likes to write stories and traveling to places, found the thing that let the pirate witch and her crews open the portal, the man sneakily followed them while trying to stay hidden from them. After following them back to the place of the Evil Pirate witch ( it can your choice of the place would look like, it can also be a hide out or a castle. ) When he starts exploring he comes across a chamber where an unconscious Human Zarina was, and the pirate witch was trying to look at her memories. The man tried to save her and the pirate witch was shocked at seeing a stranger, accidentally made Zarina lose all her memories, the man managed to knock her out why Zarina woke up, the man explained the best as he could to her, Zarina not sure if she could trust him, still went with him and they managed to find a second item that open the portal. They went in and was back in the place where the man find the portal, after that years passed and Zarina and the man got married and had a child that had strange wings like marks on the back as Zarina. One day some of the fairies, included Tinkerbell and her friends was out searching for trinkets and objects to make things out of that would be beneficial and entertaining for pixel hallow. As they searched they saw a couple with a child, Tinkerbell and her friends, Terence hid and watched them. As they watch them one of them noticed the women and soon realise it was Zarina. Shock and still hiding watch as they play and follow them home, after that they went back to report what they just witness to fairy Gary and one of the minister, ( it your choice if you want the Spring or Summer, Autumn one ) I will let you decide what will happen next, will they make Zarina remember who she was ? Will she even want to be a fairy again, will the evil pirate witch return ?

Here is a Tinkerbell idea

What if there were dark fairies that were banished by queen Clarion and Lord Milori and the Ministers of seasons ? They vow to get revenge and then went to a place that became forbidden to enter, years later after the event of Secrets of the Wings or The Pirate Fairy or the Never Beast ( it your choice of what after movie you want ) Tinkerbell on a day off or went to look for things to make. Was unknowingly near the forbidden place and was being watched by dark fairies scouts, they spy on her and have one follow her, the dark fairy was given something that makes someone invisible for 5 hours and 13 minutes. After spying and listening on the Tinkers fairies and returning, the scout reports back to the leader who is their ruler ( you can choose if you want a king or queen but for now I will say ruler ) the Ruler listens as they went back to their home to think for a while, a plan was slowly starting to form a plan. The plan was having three of the best scouts to kidnap Tinkerbell and have her use her talent to make things for them, after they kidnap her the ruler explain why she is here and what they have in mind for her. After hearing this Tinkerbell try to escape and refuse to help, hearing this the ruler shake his/her head in disappointment then have someone moved her to a room was to be kept lock under watch and was only to bring food and water. After that the ruler went to find some spell books that were taken during the banishment, some dark and forbidden spells and learning to make certain potions, why looking in some the ruler found a couple, ( it your choice of what can be ) the ruler has a couple of the dark fairies to make it. Meanwhile Tinkerbell's friends are starting to worry when they haven't heard or seen her for a day or two and ask Fairy Mary, Clank and Bobble if they seen or heard from her ? They both said no but Bobble did mention a place she talked about, they went to find someone if they know such a place, after a while they came across one of the minister ask about if he or she know the place Tinkerbell has mentioned to Bobble. After explaining the Minister told her that he or she will talk to the other ministers and queen Clarion about it. After that the next day a couple of royal guards come to bring Tinkerbell friends to queen Clarion, when they got there they was also surprised to see the ministers there as well, they explains why they were here and tell them about the place that Tinkerbell went and the history of it. I will let you choose what will happen next, will they save Tinkerbell and bring her home.

Or

there could be a dark fairy prince and he wanted her and used her talents for him and the others dark fairies, later in he soon started to have feelings for her, but she doesn't love him at all so he uses something or have someone to make something that will make her forget her old life.