This is a series of books which interlink with each other. There is no set order for these books but I would suggest (to avoid as much confusion as possible) you read in this order:

Afraid (Sirius Black)
(Started 2016, completed 2019)

Blue Belle (Fred Weasley)
(Started 2017, ongoing)

Letter's to Nancy (Charlie Weasley)
(Started 2017, ongoing)

Hidden Secrets (Bill Weasley)
(Started 2017, completed 2020)

Hate How much I love you (Sirius Black book 2)
(Started 2019, ongoing)

Can't be hidden (Bill Weasley book 2)
(Started 2020, ongoing)

The Dasa Chronicles (A hidden Secrets OC)
(Started 2019, ongoing)

BOTH SEQUELS CAN BE READ AT ANY POINT AFTER READING THE BOOK IT IS THE SEQUEL TOO)

Some of the characters I have created include:

(Afraid)
Madison Parker
Darcy Parker
Lochlan Parker
Matter Johnson
Evangeline Smith
Caleb Parker
Theo
Edvadus
Ansel
Harliana (Harley) Lupin.
Beatrice Florence

(Blue Belle)
Belle Florence
Beatrice Florence
Harliana (Harley) Lupin.
Nancy Mulligan

(Hidden Secrets)
Harliana (Harley) Lupin
Emma Lupin
Lorcan Lupin
Asa Barnes
Dylan Quinn
Roger Moore
Orlando Lupin
Xavier Hughes
Nancy Mulligan.
Beatrice Florence.